I have a bit of a problem with what your doctor said to you as well. My dear, I feared the same thing when I was at the point you are at right now. New meds, a terrible relapse, and wanting it all to end. The doctors are there to HELP. If they don't help, keep trying, go somewhere else.
I dropped my older two children off in the fall with their father so I could get myself the help I needed. I was slapped with a court order right before Christmas granting their father interim custody. I was devastated. I felt the same way you do now. I didn't know how I could possibly survive without my children.
Now, my daughter won't talk to me, my son wants to be back with me, and I have my youngest one with me. I am sober and clear headed and the pain of being on new meds and drinking has disappeared. Legally I have to take the steps to have my children back with me. And I want to. It was very rough going. I chose to drink myself through the worst of those feelings, but I am ok now.
It was very hard for me to hear over and over that it was in mine and the kids' best interests that I take care of myself and do what I needed to get better, no matter what happened. Now I have accepted that I'm never going to be a perfect mom, but I can be the best mom I can be by taking care of myself.
And part of that, in the rough times, meant using EVERY tool available to me. I spent a lot of time in hospital. I had to have safe places and safe people.
You matter very much to a lot of people. Things will get better if you keep allowing that survivor's voice to speak up and open your mind up to anything that can help. I know you are hurting so much right now. Keep leaning on those who are strong enough to support you. SO much love to you.