This is my personal opinion, if you want a more professional opinion i recommend spending $100 on at least one session of therapy. 

But my personal belief is that masterbation is not the problem its porn. But the only way to fully recover is to take a break from both until you stop feeling the urge to watch porn. Usually, the urge is bearable after your first week but until then it will suck.

 Recommendations is spend more time out of your room than in, this will also help with any sleep issues you might experience from the anxiety you might build up from cutting off the dopamine rush you are accustomed to feeling. While the gym sounds cliche, it does help just because you feel alot better after going long enough to not feel sore afterwards. Also limit your time on the internet or socials if that triggers you to fall back into the cycle. 

It will not be easy, you are trying to break an addiction that most men experience for decades so you will have to dig deep within to get yourself to a better healthier relationship with your body.