In your case it does not help much to look at how you connect with him astrologically speaking. You do not need to understand how to interact with him, what you need is to let go. The reason why you are obsessed by him is that he is a person with certain traits and behaviors that forms a key to very deep parts within you. When that happens, we feel as if we have found the one. When the person gives us confirmation, the deeper parts of us vibrates of happiness. When the person triggers deep fears and negative emotions we have, we feel horrible. We feel that the person has the power over us, the person decides whether we get to be happy or not. People who somehow remind us of our childhood can make us feel at home and we are drawn to them because it feels comfy and like we have found our way home. You both hit the others fourth house.
I used the following method when I had an extreme obsession with someone many years ago. First I stopped having contact with him. Then during a phase I wrote tons of letters to him (it´s good to write from the heart but don´t send the person letters). I had to let myself obsess and express my disappointment, my hurt feelings, the immense love I felt for him, the anger etc. Then I stopped thinking about him. When thoughts came up and I felt awful, I emptied my mind and I sank down into my body and the emotions I felt. I owned my emotions and I realized that they had been there for a long time. I asked my body the question: “when did I feel like this as a child?”. I felt feelings of worthlessness, feelings of me being unlovable, feelings of loneliness and many other things and the root cause had to do with my childhood programming. It had to do with what this world made me think and feel about myself as I was growing up. If someone has triggered very difficult feelings in us, the brain reacts by believing that the person who triggered those feelings is the only person that can make us feel better again. We believe that the person can make us whole and happy if the person returns and behaves better.
I also thought about what I admired in him. We often fall for people who have traits or talents that we have repressed within ourselves. He was very talented in certain areas and I began practicing certain skills that I envied. My intense admiration for him did diminish as I found more of the repressed parts within me.
As I grew, I grew away from him. Then I began seeing him as a selfish child instead of as an alpha male and I feel zero attraction towards him and I never think about him.
You say that he cannot stop drinking. Think about the fact that he may be as hooked to alcohol as you are to him. He may feel that it is impossible for him to live without the alcohol. If he would detach from it he would have to confront his inner feelings and that is something he does not want to do.
You ask: “what exactly are his feelings towards me?”. You ask this question because your self-value lies in his hands. If he is in love with you, you will feel lovable and like you have a soulmate who loves you. If he feels as if you are nothing, you will feel that it means that you are nothing, and that you are unlovable, worthless, not worthy of any kind of empathy, honesty and respect and many other horrendous things. You want to know what he thinks about you because you want to know the truth. I can guarantee you that the truth about your worth and the truth about who you are is something that he has no idea about. His only focus in life is to try to avoid his negative emotions through alcohol and he is trying to numb his pain by using other people. If he would have chosen another life path perhaps you would have been happy together. But everybody has their free will and we cannot change them. If he would someday stop drinking and if he would seek help you can give him another chance if you want to. But as it is now he will only bring you a lot of pain.
His Pluto is in your second house, and you have your own Pluto there as well. The second house stands for self-worth among other things. He has an impact on your sense of self-worth.
When a person goes no contact and when a person learns how to own everything that is happening within, things will get worse on an emotional level for a time. This is why the brain does not want to let go of the addiction and this is why many people go back to destructive relationships.
But if you stay connected to the roots of these emotions they will heal. The only thing emotions need in order to heal is complete presence, no fighting against them, no escapist behaviors or projections on other people. After you have processed your feelings you can rise up again and you will be transformed and no one will be able to make you his slave in the same way again. It is difficult to explain, but once you have certain boundaries, they are just there. It´s like when the immune system has learnt to fight a certain virus, it will just do it without you taking any sort of action.
I know what it feels like to be in your situation and I am sending you strength. I really hope that things will feel a little better soon!
You could post your transits if you want to and/or your natal. That is more helpful to look at in this situation.