I have asked myself the same questions you are asking a million times. It takes what it takes.
Don't give up on yourself and don't think that because you keep going back to alcohol that all is lost. Yes, I too have felt beaten down. So, what are you going to do?
You said you dumped your sponsor a few weeks back thinking you could do this on your own. Is that truthful now? Are you willing to go back to a meeting and do what you know has worked in the past? Relapse is a part of alcoholism. It is not every alcoholics road but it is for some. It has been for me. Chronic relapser here.
Your ex is feeding you a bunch of ********, to be honest. I would seriously consider the source. I mean, he is drinking a bottle of wine a night. A bottle of wine. That is a lot of alcohol, girl!