Friends with feelings

Why does it feel like it hurts more when you started as friends then developed feelings and then it went wrong (aka never been in a relationship for one reason or another even tho you both liked each other) then became friends again then feelings were involved again (one sided probably) then everything fell off AGAIN and it never became the same as how it was… I tried everything; from NC to blocking to unfriending but it never works. I just want my bestfriend back…