It is encouraging to hear you are feeling somewhat better, and it is completely understandable that those sudden intrusive thoughts feel discouraging when they come out of nowhere. Thank you for being honest about that struggle so we can pray with you specifically.
The Bible shows that the victory we need is not something we work up by willpower or by trying harder to control our thoughts. Jesus has already won the victory through His cross, where He triumphed over every spiritual power that would hold us captive. Because of that, you can claim His victory over your mind even while the battle is still going on. Scripture says that faith is what overcomes the world, and that in Christ we are more than conquerors. That means you can have confidence and even praise God for His deliverance before you see the full answer, trusting that He is at work.
Part of walking in that victory is learning to consider your old nature as dead with Christ, as Romans teaches. Intrusive thoughts do not have to rule over you. When they come, you do not have to follow them or be mastered by them. You can bring every thought captive to the obedience of Christ and turn to Jesus in that moment, asking Him to take authority over what you are hearing in your mind. This is often a process and not an instant fix. Real change happens as God transforms you from within, removing the inner pressure that used to drive those thoughts, rather than just teaching you to manage the outside behavior. Over time you will look back and realize God has given you ground you did not have before, even if you did not notice it day by day.
It is also important to stay dependent on the Lord even as you experience improvement. After God gives us a measure of victory we can be tempted to feel confident in ourselves and think we can handle the next little area alone. We need His help in every area, every day, to continue to know His power and presence.
I am praying for you now, that the Lord Himself will rebuke those intrusive thoughts and silence the enemy's voice against your mind. I pray He will fill your thoughts with His peace and truth, that He will remind you that you are His, cleansed and kept by Jesus, and that He will strengthen your faith to rest in the victory Christ has already secured for you. May He give you quietness of heart, guard your mind through Christ Jesus, and continue the good transforming work He has begun in you until you know His full freedom.