Sobriety isn't a straight line. But no matter what bumps and curves you hit along the way, try to move in the right direction. You know what to do. You have already done it.
Someone told me this at a meeting and it stuck: 'the pain is real but the suffering is optional.' Take it or leave it.
Also consider how hard you are really working AA. Perhaps you are. But maybe you could go to more meetings? Find a new sponsor? Keep yourself occupied with meetings and stepwork.
You have gone through so much already, it would be a shame to quit now if there is more that you can do. Through your desperation and lonelieness I hear an intelligent person with a good heart who unambiguously wants to be sober. Hang on to it like a cliff face.