Congratulations! 90 days is a huge accomplishment! Some of the best advice I heard: to get self-esteem you have make esteemable acts. Another thing: feelings aren't facts. Just because you think this way doesn't mean you're a failure. For me it helped to try to get out of my own screwed up head as possible. Got very active, went to a ton of meetings. Here's a guarantee: by staying sober you will do amazing things in life.