hi im sorry to hear what happened to you ,it must be very disappointing to you after 3 solid yers to fall, if it helps any,i fell after 11 years unfortunately(i was in kollel for 10 years when i fell ),i(little not expert me) would say -just move on-youll deal with falling for a later day.
may i ask 2 questions
1.if youre learning all day ,what do you mean that your not doing aseh tov,thats the biggest aseh tov there is?
2.what do you mean that your doing sur mayra the whole time,are thoughts constantly bothering you?
please dont let the thought, i just fell ,what good is my learning,davening etc....im tamei....,enter your mind ,its not true ,your avodas Hashem is very chaviv in the eyes of Hashem the sefer Nefesh Hachaim says that Talmud Torah fixes up all aveiros including this,the streets are full of tuma ,we have no one being mechazek us ,we are a dor yasom,an orphaned generation,whatever you could do ,do ,dont let the yetzer hara be mevalbel,confuse,your thoughts.the best i would say is if you have a Rebbi, or a Gadol,to talk to him.BH you found gye when you fell, i hope you can find what you came looking for here.Chazak Chazak!