Struggling with indecent thoughts and sexual impulses

So here is my first thread I guess on nofap, forgive me if I am doing anything wrong or if there is something that I need to do first as a newbie but however I am struggling with a problem that won't shutup.

Here is the problem, I try my best to quit however I as of now I can only stop myself for at least 3 days at a time, rarely a week.

My problem is that I work out frequently, I try my best to keep my self busy, I have school, working out, clubs and etc. but however sometimes what happens is that after a few days when I take a nap or try to sleep I get a sudden rush of indecent thoughts and a very uncomfortable pain in my chest, I try my best to resist but to no avail, its like I won't be thinking about any thing sexual and in the next moment I am suddenly finding myself in front of the computer, trying to get rid of the pain my chest

Believe me I have tried my best to struggle with these sudden impulses but man there are just too much just to ignore. I also sometimes struggle with dealing with indecent thoughts in my day to day life as well, controlling the mind and the thoughts that enter it is a very hard task

If someone has a solution for me or even advice please tell me, I would really appreciate it