Your cry for mercy is the right place to begin, because we never come to God on the ground of getting what we deserve. Justice is getting what we deserve, mercy is not getting what we deserve, and grace is getting what we do not deserve. We come for mercy and grace through Jesus Christ alone, and Scripture says blessed are the merciful for they shall obtain mercy, and that mercy rejoices against judgment. God has said, I will have mercy on whom I will have mercy, and it is not of him who wills or runs but of God who shows mercy.
You are right that God knows this unspoken prayer. Prayer is not informing God of something He does not know, for your Father knows what you need before you ask Him. Prayer is aligning your heart with His will and purpose so that His will may be done. He hears even when you do not speak the details aloud, and He is not limited by distance or circumstance. You can bring this burden to Him in the name of Jesus alone, trusting His sovereignty and goodness to answer according to His perfect will.
It hurts to be mocked for praying, and mockery is often used to discourage those who seek God. The faithful response is not to return insult or to judge without mercy, for he who judges without mercy will be shown no mercy. The better way is to answer mockery with prayer, as Nehemiah did when he was despised, and then to continue walking responsibly before God. Prayer was never meant to take the place of faithful obedience. We pray and we also watch and walk wisely, and we refuse to let fear drive out faith, for fear and faith cannot rule the heart together.
You said you must believe your prayer has already been answered. True faith is the substance of things hoped for, the evidence of things not seen, and without faith it is impossible to please God. Yet saying we have faith is not the same as having living faith. Scripture teaches that we are saved by grace through faith alone, not by works, but that genuine faith will always show itself in a changed life and obedient works. Faith works together with obedience and is made complete by it, as we see when Abraham trusted God and obeyed. If faith has no evidence in the life, it is dead and cannot save. At the same time, lapses do not disqualify you. Abraham himself had moments of faltering, yet God still called him a man of faith. Some of the most faithful in Scripture died in faith not having received the promise in their lifetime, still trusting God. So hold fast to Jesus, trust His word, and let your faith be active, patient, and surrendered to what God knows is best, not merely to getting your own will done on earth.
Persecution and opposition arose very early for those who followed Christ, yet in those trials their faith grew exceedingly and their love for one another abounded. God can use even this painful experience to deepen your faith and your love. My prayer for you is that God would count you worthy of His calling and fulfill in you every good pleasure of His goodness and the work of faith with power, that you would continue steadfast in faith in Jesus Christ and not be moved by affliction or by the words of others.
In the name of Jesus I pray that the Lord would have mercy upon you, grant you a living and enduring faith, guard your heart from fear and bitterness toward those who mocked you, and bring about His perfect will in this unspoken matter for His glory and your good. May you seek His mercy, rest in His grace, and walk in obedience that demonstrates the reality of your trust in Him.