Guilt was my largest piece of baggage I brought into recovery, more over what I had done to others than myself, though obviously I had let myself down badly as well. Forgiving myself seems to be the pat answer to your question but actually it turned out...
First I admitted the problem and took action on it. I took a long hard look at myself and acknowledged what an ugly individual I had become. I told all my shameful secrets to another human being and became willing to change into a better person and try to get rid of my selfishness. Then I went out and made a serious effort to repair the damage I had done, paid old debts, made restitution and healed emotional harm. I asked forgiveness of those I had hurt and showed contrition and resolved never to behave that way again.
After that I looked around and found, as far as self forgiveness was concerned, there was nothing left to forgive. I had done my utmost to straighten out the past and could now move forward with no guilt and no skeletons in the closet. That felt great.