Ok i started no fap and it was helping me and i had good streaks but . Long story short
Last months ive seen a girl in my class in university . Shes really sexy and im adicted to imagine her body and fap
And the problem is i will see her again and again for months
Give me the path please
Also know that she is already married and i cant ask her for sex
So this thoughts …
The first thing that goes without saying is to try and put some distance between you both, I know that may be difficult especially if you share classes, but it’s worth mentioning, out of sight out of mind.
Second and personally I find quite effective, think of something that would really turn you off about anyone in general, so bad that no way you would go there with that person, then imagine that she has / does / likes / etc that thing, something to keep to yourself obviously, but every time you think of her think also of the thing applied to her, in short time you shouldn’t think of her so much.
And if you haven’t already I would recommend some meditation, a daily routine is not only helpful all round with all sorts of benefits but in this case it helps you to develop some tools to help keep you mind in check, I’m at a point 95% of the time that I can have a thought come up and I can literally say / think to myself no I will not indulge this thought and my mind just drops what it was thinking and moves onto something else, a handy trick when surprise thoughts and urges crop up 
Best of luck, I hope this helps.