Serious 30 days challenge. Day 0

hey guys, i'm new here. 23 years old, doing masters in history. i hv been addicted to porn and musterbation for last 3 or 4 years. The first 2 years felt amazing, i didn't feel any guilty or any problem. But from last year came to knew the side effects of this thing. I couldn't concentrate on my studies, my grades are getting low, i feel lack of confidence. whenever i see a attractive girl or woman my mind automatically thinks about sex, then i feel guilty and ashamed on my own thoughts. I know, if I stay like this, my future is going to be hell. I really need to get out of this. I hv researched a lot and I came here.
So I'm starting NoFap challenge from today for 30 days. Starting small, one step at a time. I'll complete this and then I'll start for 90 days.
counting from today. Day zero 0.