I have homosexuality problem having done sex with the same sex many times since I was 12. Now I'm 19. What should I do? Please suggest to me anything worthwhile and helpful to me because I consider it a sin.
Sin is defined by God. Whether you or I consider something to be sinful or not doesn't change that thing's nature. God defined righteous sex to take place between a husband and wife. "Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge" (Hebrews 13:4). Therefore, homosexuality is a sin, just as fornication (sex between an unmarried man and woman) is a sin. "Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites,nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners will inherit the kingdom of God" (I Corinthians 6:9-10).
All sin is a breaking of God's law. That means it is a choice that you made, no different from the choice a guy makes to have sex with his girlfriend. While the desire to sin is strong, it does mean you can choose not to sin.
The first steps are to change your life and become a Christian. Right after pointing out all these sins, Paul told the Corinthians, "And such were some of you. But you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus and by the Spirit of our God" (I Corinthians 6:11). See: How to Become a Christian. Becoming a Christian won't stop your desires for sex, but it will forgive you of your past sins. Becoming a Christian doesn't mean you will stop sinning in the future, but it is a statement that you are going to fight sin and enlist God's aid in battling sin. It also means you will have fellow Christians to help you in your struggles against sin.
Therefore, along with becoming a Christian, you have to change. The people you hang around with will have to change because they are likely to lead you back into your old sins. Things that encourage sexual sins, such as pornography has to stop. For a while it will be hard replacing your old bad habits with good habits, but if you are determined, it will happen. The biggest change is realizing that you should not make decisions based on your feelings and desires. You have to look at each situation and decide what is the right thing to do, according to God, regardless of your personal feelings about the matter.
Thanks for your reply! The situation is that I have tried many times to stop myself when he is in close proximity to me. I want to know how can I stop my desires at that moment.
Behind your question is a belief that you must do what you feel. Instead of making rational decisions, you let your body's impulses and desires determine your choices. This is how Satan snags all people into sinning. He offers them what they desire, they focus on that desire and never stop to think that the offer involves committing sin.
Desires for sex are always going to be there. It is a part of being a human. Since you have trained yourself to express those sexual desires with another male, the natural inclination will be to repeat what you've done in the past. Therefore, you have to deny yourself and put God first in your choices. "For the grace of God that brings salvation has appeared to all men, teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly in the present age" (Titus 2:11-12). In other words, you have to learn to say "No" because something is wrong.
Now if it someone is tempting you to sin, the best solution is to get that person out of your life. It is hard enough to make good decisions when someone is pushing you to make bad ones.