Can you PM me and tell me what country and city you are in? Aside from the interest because I love Europe, I could look and see if there is Al-Anon available where you are. Of course you could do this yourself too
It IS horrible and anxiety-producing and depressing and all sorts of debilitating and life-sucking things to be involved with an alcoholic and be presented with their chaotic and selfish behaviors. They are very sick people and sick people will make you sick. Literally.
The only way I know to deal with what you are dealing with, to deal with alcoholics and addicts, is once you become aware that being in your relationship with him is negatively affecting you, cut all contact with him. Deal with YOU. Deal with the panic and the anxiety that separation causes in healthy ways. By running and exercising, by seeing mental health professionals, by going to Al-Anon as much as you can, by taking care of you and implementing routine and predictability into your days, by surrounding yourself with positive and supportive people, by talking about what you are going through.
It makes sense to me that you are having difficulty focusing on your dissertation. Pick a day or half a day or an hour a day, as much as you can devote, and focus solely on YOUR needs, YOU, what YOU like, what YOU dislike, what brings YOU peace. Start small, but start somewhere, anywhere. Sit in the silence and listen to your body. Meditate. If you don't know how, sit in a chair, shut off all sources of noise, close your eyes, and picture a burning candle flame inside your forehead, and focus on that flame. Each time you feel your thoughts wander or rushing around in your head, bring the focus back to the flame. Just keep practicing this as much as possible, even while writing for your dissertation, and soon you will become in touch with your needs. And then, take immediate action to satisfy that need as quickly as possible.