I feel deeply shame while I'm saying this. through my whole life I know that lust is sin and shouldn't get into our mind but lately I think mostly about it. I feel like it's controlling my life even though I exert so much effort to remove these ideas temptation is much stronger.I'm really afraid to fall in sin.
The bible tells us:
Php 4:8 Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.
and
Mat 26:41 Watch and pray, that ye enter not into temptation: the spirit indeed is willing, but the flesh is weak.
I would suggest that you spend some time each day praising God, and seeking Him. Thanking Him for the good that He has planned for your life. Try to fill your life with positive thoughts. God can meet your needs in this time, and He will certainly meet your eternal needs.
When I was single, and under a lot of pressure to sin. I would walk around my room declaring "I know you have good plans for me God". At the time all seemed impossible, and I had no hope. But God gave me hope. Now I have that hope, in reality. Lust was powerful, and some times I fell. But I always cried out to God for help.
Psa 145:16-19
By your own hand you satisfy the desires of all who live. Our LORD, everything you do is kind and thoughtful, and you are near to everyone whose prayers are sincere. You satisfy the desires of all your worshipers, and you come to save them when they ask for help.