We have heard your cry and we are standing with you in prayer together in Jesus' name, for you are not alone in this battle and our God sees all that you are enduring.
We want to speak first about the spiritual warfare you described. The Word tells us For our wrestling is not against flesh and blood, but against the principalities, against the powers, against the world's rulers of the darkness of this age, and against the spiritual forces of wickedness in the heavenly places Ephesians 6:12. Witchcraft, sorcery and any attempt to attach oneself to another or to steal what God has given is an abomination to the Lord as it is written There shall not be found with you anyone who makes his son or his daughter to pass through the fire, one who uses divination, one who practices sorcery, or an enchanter, or a sorcerer, or a charmer, or a consulter with a familiar spirit, or a wizard, or a necromancer. For whoever does these things is an abomination to Yahweh Deuteronomy 18:10-12. We rebuke that witchcraft and every assignment of the enemy against you, and we declare that it has no authority over a child of God. You do not need to live in fear that someone can steal your energy or your destiny, for when you are in Christ your life and your future are hidden and secured in Him. As it is written You are of God, little children, and have overcome them, because greater is he who is in you than he who is in the world 1 John 4:4 and No weapon that is formed against you will prevail Isaiah 54:17. The sickness and weakness you feel when you pray is real oppression, but God has not given us a spirit of fear, but of power, love, and self-control 2 Timothy 1:7. We encourage you to submit yourself fully to God daily, to resist the devil and he will flee from you James 4:7, to put on the whole armor of God Ephesians 6:11, to fill your home with worship and the spoken Word, to fast and pray as you are able, and to stay connected to a Bible believing church where mature believers can pray with you in person. Do not seek answers through dreams, visions, or spiritualists for guidance, but test everything by the Word of God.
We also want to lovingly address your mention of your ex. We do not know all the details of that relationship, but we must speak the truth in love. God designed sexual intimacy to be within the covenant of marriage between one man and one woman for life. Any sexual relationship outside of that marriage is fornication or adultery and opens the door to spiritual bondage and ungodly soul ties. If there was sexual immorality in that relationship, we encourage you to repent before the Lord, to renounce any ungodly tie in Jesus' name, and to ask God to cleanse you and make you whole. We pray that if you desire a relationship in the future, you will pursue courtship with the goal of marriage to a fellow believer in Christ, for a godly marriage honors God and protects your heart.
Concerning your neighbors and your living situation, we grieve with you over this ongoing suffering. Your body is a temple of the Holy Spirit 1 Corinthians 6:19-20 and to be constantly exposed to drugs and smoke to the point of dizziness and nausea for three months is harmful and unjust. It was right for you to speak to them and to your landlord, and it is right to continue to seek help through proper channels. We encourage you to document what is happening, to make a written report to your landlord, and if needed to contact local housing authorities or health departments, while also protecting your health and seeking medical care if these physical symptoms continue. We will pray for your neighbors as well, that God would deliver them from drug use and bring them to repentance, for God desires all to come to the knowledge of the truth.
We noticed your request did not mention the name of Jesus Christ, and we must gently tell you that it is only through Jesus that we have access to the Father and that we are saved. Jesus said to him, I am the way, the truth, and the life. No one comes to the Father, except through me John 14:6 and There is salvation in none other, for neither is there any other name under heaven, that is given among men, by which we must be saved Acts 4:12. If you have not already done so, we urge you to place your faith in Jesus Christ, to believe that He died for your sins and rose again, to confess Him as Lord, and to call upon His name. If you confess with your mouth that Jesus is Lord, and believe in your heart that God raised him from the dead, you will be saved Romans 10:9. It is by the powerful name of Jesus that we can rebuke darkness and be delivered.
So together we pray.
Father in heaven, we come before You in the mighty name of Jesus Christ, and we lift up our sister to Your throne of grace. We thank You that You are her refuge and fortress, He who dwells in the secret place of the Most High will rest in the shadow of the Almighty Psalm 91:1. We ask for Your forgiveness where there has been sin and we ask You to cleanse her by the blood of Jesus and break every ungodly soul tie and every work of witchcraft and sorcery sent against her. We rebuke the enemy and every spirit of infirmity, oppression, fear and confusion, and we command it to leave in Jesus' name. Fill her with Your Holy Spirit, with power, love and a sound mind, and let her feel Your peace that surpasses all understanding Philippians 4:7. Touch her body and heal the dizziness, nausea and weakness, and strengthen her each time she prays so she will not grow weary.
Lord we also bring her housing situation before You. You see the injustice and the disrespect she has endured and You know her need for a safe and clean home. We ask that You would convict her neighbors and her landlord to do what is right, or if it is Your will, open a door for her to find a new apartment that is peaceful and free from defilement. My God will supply every need of yours according to his riches in glory in Christ Jesus Philippians 4:19, so we ask You to provide the resources, funds, favor and guidance to move to a better situation. Lead her to a place where she can dwell in peace and worship You without hindrance. We also pray for the salvation and deliverance of her neighbors, that they would be set free from drugs and come to know Jesus.
We declare that You are greater than all warfare and that nothing can separate us from Your love Romans 8:38-39. Help her to walk in holiness, to keep her eyes on Jesus, and to trust that You are working all things for her good. We ask all of this in the precious and powerful name of Jesus Christ, our Lord and Savior, amen.
Prayer Focus: God, Thank You for loving me. Thank You for loving me, Jesus. God, I ask You in Jesus’ name please bless me with everything that I stand in need of and everything You want me to have. God bless me to prosper, walk in excellent health, and never stop growing in the love, grace, wisdom, and knowledge of Christ Jesus. God bless me to know You in truth, fall in love with You with all my heart, mind, soul, body, and strength and never fall out of love with You. God, bless me to have an ever growing closer stronger, more intimate relationship with You. Bless me with the love, desire, strength, and the spirit of obedience to always delight myself in You, seek first Your kingdom, Your righteousness, and to always respect and obey You. Bless me to know You, the way You want me to know You. So that I will trust You with my life and anyway that You move in my life. Bless me to trust You with all my heart, lean not to my own understanding, acknowledge You in all my ways, and allow You to direct my footsteps and actions. Bless me with knowledge, wisdom, and understanding in all You have called me to do. 
