Your desire to honor God in this relationship is beautiful and He sees it. Choosing to reserve living together and physical intimacy for the covenant of marriage is obedience, and it honors the way God designed marriage when He said the two shall become one flesh. That oneness is a profound unity, two persons becoming one, reflecting something of His own nature as one God. Wanting that kind of holy union is right before Him.
It is also understandable that you feel discouraged when every time you get close to seeing each other an obstacle arises. Scripture tells us that everyone who wants to live a godly life in Christ will face opposition. When you set your heart to do things God's way, you should expect resistance. The enemy does not oppose what does not threaten him, but a marriage built on purity and commitment to Christ does.
Jesus described this in the picture of seed sown on different soils. Some hear with joy but have no root, so when pressure comes they fade. Other seed is choked by thorns and cares. A godly intention needs deep roots to endure testing, and that depth only comes from a personal, daily walk with Jesus, not just from good desires or a Christian background.
There is also the constant battle between the flesh and the spirit. It is not surprising when the flesh feels stronger, because we are so faithful to feed the body and so often neglect to feed the spirit. If the spirit is undernourished, it will struggle in the moment of temptation or disappointment. Prayer and fasting help reverse that pattern. They quiet the demands of the flesh and strengthen the spirit, so that the spirit can lead.
In this season, keep feeding your spirit together and separately. Stay in the Word daily, pray consistently, and even set aside times of prayer and fasting to seek God for clarity, provision, and protection over your relationship. Keep clear boundaries that protect purity, stay accountable to mature believers who can encourage you, and keep bringing the practical hindrances to the Lord.
I pray that God will remove what needs to be removed and establish what needs to be established according to His perfect will and timing. May He guard you both in purity, provide for every step toward a lawful and lifelong covenant if it is His will to join you together, give you patience and peace while you wait, and let your union, if He brings it to pass, be built on Christ and bring glory to Him.