I struggle with being too hard on myself too. It's a hard habit to break. Be kind to yourself. It's a long journey, but worthwhile. I still need to remind myself everyday. Plus, I've chosen to accept that for me, the band is not a miracle worker, but it was the catalyst to get me and keep me on a good path. (not a perfect non cheating path, either!)
No matter what your goals are, you'll get there.