Fox - you rock. You are doing so well!
Hope oh, love. I'm sorry things are so crap for you right now. I fully identify with your anxiety symptoms - I often felt as if I was running in a hamster wheel. Wine was the only thing that ever allowed me to slow down and get off for a bit. But, you said it yourself - it's not the answer, and it will only actually increase your anxiety in the end.
As you know, your son is right about the running 
JFDI! Have you seen the This Girl Can ad campaign? There's one in a bus shelter I drive past on my way to the gym, it says "sweating like a pig, feeling like a fox". It always makes me smile and spurs me on. A while ago, a girl came in the gym changing room all of a flutter, because one of the big muscly oily men in the weights bit had asked for her number. I saw her there again the next night, wearing all new flashy gym kit and six inches of makeup, pedaling veeeeeery slowly in a presumed attempt to remain pristine and polished. And I found that impossibly sad. Get out there and get sweaty, do it for you, you fox!
Another January phenomenon at the gym is the influx of people who clearly haven't gymed for a while. They have no fancy kit, they're going pretty slowly and they're looking wasted. And I always give them an internal cheer and think well done you for hauling arse off the sofa and getting out here. You go. Obv I never say that out loud, as it's pretty patronising really. But you get the idea 
Baby wow, I find yours a very inspiring post. You are doing so well. As the trite old saying goes: everyone slips and falls sometimes, what matters is picking yourself up and trying again. And boy, do I know what that feels like. My latest self-pity party joke is that I'm amazingly good at giving up alcohol, cos I've done it so many times 
yeah, I know, it's not even funny is it?
Yesterday, especially after the meeting, I was full of strength and optimism. Today, even though I've had a pretty lovely day and DH is being so great to me as he's so proud that I've finally admitted that I am an alcoholic and gone to AA...the doubts are creeping back and that mother fucking old bitch the WW is sitting on my shoulder again, tempting me. Bargaining with me. Maybe sobriety doesn't have to be for ever...maybe I can go back to social drinking some day...maybe it's ok to drink if no one else, especially DH, finds out.
Fuck.
Off.
Why is this like the least fun merry go round there's ever been? How the fuck do I get off? I AM NOT HAVING FUN ANY MORE.
ma that's heartbreaking about your dad. Poor man. I feel for your DH as well, it's an unenviable position, but it's clearly over between you...ffs why is he trying to hang on? Has he no dignity at all? Does he actually love you so little that he'd rather you were with him and unhappy, than away from him? Because that's not love, now is it.