You arre definitely not alone, the quitting for 2 years thing and then wondering why you can't do it again is something i have seen a few times actually...have you thought about approaching someone who has long term sobriety and emulating what they have done? IMO your most important lesson here, regardless ot your circumstances, is that if you could have quit and stay stopped by yourself you would not have picked up after 2 years...reach out for help:-)