Autism and estranged son

I'm 40 and I've always felt a bit different, and I seem to fail at relationships/Marriage and even the relationship with my teenage son who I haven't seen in a year. I've always suffered with anxiety and having relationships with people.I recently sought a referral  from my GP, and I've just had my initial consultation with an outside organisation.  I split up with my ex-husband about four years ago, after he beat me up and because I told me people, he and his family have not spoken to me since. I really have no idea why he isn't speaking to me, our marriage was far from perfect but surely I should be the one who's mad.  I was the one who wanted out of the 19 year relationship and my husband wanted to stay married. I would've left far earlier, but I was virtually agoraphobic when I was married and scared to go out. Things were very difficult after I was on my own as single mom. I developed a drink problem, although I was a functioning alcoholic and smoked cannabis, all to mask the way I was feeling. I was deeply stressed and suffering from anxiety that I was also perscribed Prozac. I was a bit of a mess, but thought I was coping as i was holding down a good job, still taking the kids on holidays etc. I found a new partner, who wasn't good for me and the kids. My eldest son started playing up at school  (suspected Autism, which his dad wouldn't agree with ) and I told him to live with his dad. He did, and never came back. I'm obvioulsy heartbroken and tried to get him back but he ignores me and his dad is happy about all this. He's happy that i'm struggling. I've since stopped drinking, taking drugs/prozac, split up with the old boyfriend and trying to get myself well again. I just feel awful, about myself, the whole situation as I'm so confused about why people won't just get over what happen. My son doesn't have any feelings for me, even though it was pretty much just me and him as a child, as his dad was constantly at work. I even paid hundreds of pounds to take his dad to court so the HE would see his kids, and commit to regular times, as when we first split up he kept letting them down.  I just have no idea how to make friends, have a proper relationship. I'm so confused