Hey, just know that this is normal and you aren't crazy. Just know that nothing from your body is so impure that you'd be sent directly to hell if it ends up anywhere. Everyone gets obsessive thoughts but make sure to be stronger and not listen to them because if you pay attention to them, you'll end up in a disturbing mental state that would be increasingly harder to escape. Make your mind a stronger fortress (by practicing ignoring these thoughts) no matter how much you feel that cleaning up is a responsible thing to do. Your mind will come up with ways to convince you to do irrational things but it is your responsibility to ignore them and do what you think is the saner thing to do. It's not going to be easy but it is much easier than getting out of whatever terrible situation listening to this train of thought will put you in. Also, you know the cleaning is wrong because not a lot of people are doing it so anytime you're confused about the right thing to do, just try to take some cues from people around you. I'm not telling you to always ignore your conscience but I'm just telling you that cleaning up obsessively in this scenario is extremely harmful, irrational and unnecessary. It can be hard sometimes to figure out if your conscience is leading you in the right direction or if it's just your mind messing with you. In that case, make sure to communicate with people. That's extremely important. I still urge you to talk to someone irl no matter how daunting that may feel. If you keep this stuff to yourself you're bound to implode so don't be afraid to talk to someone. When a door might be to hard to open it is perfectly alright to ask someone to help open it and simply walk through. While it is normal to masturbate once in a while, I strongly advise you to not do it frequently as it will hinder your performance as a student. Also, stay away from pornography. It is an industry that is quite wickedly normalised but also destroys lives like nothing I've seen before, both for people watching and for people involved (A shockingly large number of whom are in the industry without consent or choice and are unable to leave because of some individuals watching and supporting the industry). Now that I've told you to stay away from pornography and warned you about excessive masturbation, I would also like to state that your issue of cleaning up IS NOT RELATED to masturbation (Atleast not directly) and that it is just your mind messing with you. You could've had these obsessive thoughts related to any other activity. I only gave you that extra tidbit about masturbation and pornography as extra student advise that everyone our age should use and it wasn't very very related to your condition. I just wanted to give this info to other students because I personally know a LOT of people that needed that advise at the right time.
Finally, I would also like to say that if my words were a little harsh, it was because I went through THE EXACT SAME THING a like 2 years ago no cap. I exposed my hands to so much soap that I ended up getting eczema, which swole up my hands and wrists with red patches (sometimes they were entirely swollen and red) and cuts. It wasn't great and I learnt the importance of having a strong resolve, self-control and good mental strength the hard way by seeing first hand that the strength needed to overcome a bad thought process and mental state and being mentally strong is MUCH smaller than the strength needed to endure the consequences that come from not discipling your mind and listening to all the irrational things it says. Since you are a probably Indian (Judging from your name, I'm not trying to be racist haha) If a cricket umpire keeps listening to the players that beg him to say it's an out for the rival batsmen for every ball, he'll soon be out of a job. So don't listen to everything your mind urges you to do. If you do that enough and train your brain, it will end up being your friend and not your enemy. So right now, recognize how dangerous it is to have a member of your own army (Your brain) be against yourself (Your goals) and be wise and strong to ignore your brain's irrational thoughts. It is your only option if you want to leave a peaceful and successful life! All the best, I know you can do this, anyone facing this issue can overcome it. And remember that some sensible balance is the most important thing in life, extremes will never do you any good. Don't pay much heed to your harmful thoughts and focus on what's important and crucial; your academic life. Be focused but don't be stressed, be peaceful, calm and get back to work little bro! Good luck for everything that lies ahead.
I know this is long BUT READ THE WHOLE THING! <3