I know exactly where you are coming from. I'm also a chronic relapser, I started again with day 1 today. Personally, I am in AA so I know my problem stems from not really accepting step 1 -- admitting that I am powerless over alcohol -- because every time I have relapsed it's because I told myself I could just have one glass of wine to get through the panic attack, loneliness, etc... and three days later I was in my bed having been drinking the entire time.
I know you feel ashamed, but AA meetings can really help with that because you meet a lot of people who have the same problem you do, and you see that many of them are very smart, professional people who just have a disease. It's so important not to feel alone in recovery and even if you don't agree with doing the 12 steps etc., AA is a great place to just go and not feel alone.
Good luck and just keep trying. You can do it.
GG