I am 21male.i have a problem i am thinking about sex & sexual fantasy during free time, when sleeping in bed or when looked at a young maid, prostitute!?

Normal: There have been studies showing that a young male in their sexual prime thinks about sex about every 7 seconds. Some people would think this actually too long. The question is whether this thinking is harming your life direction or your relationships. If it's causing dysfunction for you, then you should explore help. Otherwise, it's very normal.

Sex fantasy : It might be normal to think about sex in a 21 y/o male, but if it disturbs your function at work or at your class it should be checked.

This is healthy: Hopefully, you've been horny like this since you hit puberty. You can keep things under control by masturbating like every other guy does -- hopefully you've already discovered this. It's healthy and all the claims the claims that it's bad for you or is unspiritual are just bunk to frighten you. Maybe you'll find a special person to love -- but even then, you'll still look. Embrace being a man.