Getting and staying sober is not easy when we have drank for so long. I cannot give advice on withdrawals other then see your doctor, but I might be able to help with the 3 on 2 off you seem to be doing.
The first few times I tried to sober up and quit drinking I did the same thing, and it is emotionally hard. All I kept thinking was "why can't I stop", best thing I did was to ACCEPT that I couldn't stop without questioning WHY, and then deal with things as they came up. Cravings, triggers etc.
If you get a craving for alcohol, because of being bored, lonely or not caring, try replacing the alcohol with something sugary. Instead of drinking 9 beers, eat a bag of candy (I was partial to gummy bears/skittles while I was sobering up). They helped nip the cravings in the bud every time, and I still am not sure why haha.
The best way to keep motivated during sobriety is to journal out or just remember how crumby you felt while drinking, how miserable and out of control it made you feel. Then when you need some motivation re-read it or just recount all of those feelings.
Remember that life without alcohol is better then life with, for those of us who can't stop when we want to.