I guess I had similar experience on my first serious attempt to sober up. It started with 70 days in rehab, which was pretty easy, but when I got back into the world, the wheels began falling off quite quickly. The next 80 or 90 days were a steady descent into the sort of thing you describe, loads of anxiety and in the end I could not get out of bed. Almost paralyzed with fear. In terms of recovery work I was doing absolutely zero and had rejected all offers of help, believing that I could fix my own problems. I could not.
A year or so later I had joined the AA program of action and was very much surprised to find myself at the 90 day mark and things were looking really good. I never drank again and. while I have been through some rough spots, have never been back to that awful misery of when I was trying to fix myself.
Why such a big difference in results from the different approaches? Here's my theory The AA experience suggests that when we straighten out spiritually, physical and mental healing follows. By that I mean when we get right with ourselves and the world around us, it relieves a massive amount of pressure. I brought a lot of baggage into sobriety. Memories of things I did that disgusted me, people I hurt, lots of unresolved issues that kept me in a constant state of fear and anxiety, wondering what would happen if someone found out, what if I accidentally bumped into someone from the past, just always looking over my shoulder etc.
On my first attempt I just tried to ignore or deny those issues, thinking that if I would just not drink, everything else would get better. It didn't, it got worse. On my second attempt I did the things I had refused to do previously. I wasn't unique in that regard. Nobody likes what is involved in the AA program at the start. We pretty much all wish there was an easier way, But there was not. I did not understand why certain things were necessary, much of it seemed counter intuitive but I was out of options. I found that understanding, in this case, came from doing.