Breathe. Take a few deep deep breaths.
Let's deal with some basic truths, sweetie.
1. You are not whatever he is calling you. (Personally, I think that people who wind up with alcoholics are very kind people--they have to be saints to deal with the A in their lives.)
2. You are not going to be able to change this man (only he can do that).
3. Greyhounds are the best (I have three). (Just threw that in to make you smile.)
4. You need support and you are reaching out here because you know that already.
Others have said this but I will repeat it because it is worth repeating. Alanon is a group of people who have dealt with what you are dealing with. They can share their stories and demonstrat how they survived. There are also Alateen groups to help your son cope with his A stepfather. There are Family Alanon groups to help you both.
Learn. The one thing that really hit me is how the behaviors of alcoholics are all so similar. They lash out because they know what they are doing, they hate what they are doing, and they can't stop. They despise themselves for the crappy things they do and we (family) are constant reminders of how terrible they are. If you feel you cannot leave (and that is a decision only you can make), you need the coping skills to stay.
Little coping skills that I use.
When my A son says horrible things, I tell myself "That is the disease talking--it is NOT the person I raised and love."
When he gets arguementative, I tell myself "I cannot argue with a disease and I cannot argue with someone who is making absolutely NO sense."
When he starts his rants, I don't say a word (waste of breath), I just walk away.
These little things help me feel that I have control of me because I have alsolutely no control of him and no control over his drinking. But I do have a measure of control of my environment. Even that little bit of control feels good. Really. Be good to YOU. You deserve that.
And consider finding a good Alanon group. They will wrap you in their compassion and help you begin to heal. If you don't feel comfortable with the first group you try, try another one.....keep going back until you find the support you so desparately need. There may be some people there that you can't relate to, there may be people there that you don't agree with, there may be people there that you do not like BUT there WILL be someone there you can connect with......take what you need and leave the rest. That's ok.
The literature that they have at Alanon is also wonderful. If you can't go to the meetings as often as you'd like, get the books. You may not "get it" at first. I sure didn't. But slowly it starts to sink in.
Gentle hugs to you.