Sorry to hear you are sick, and that you are feeling skeptical of DB. It's not guaranteed to work, but it's the BEST thing you can do right now. Pursuing will not work, nor will anger. Reading through your posts, you're having a hard time detaching and tend to fling barbs at H about his OW. That's normal and human, and it probably makes you feel better in the moment, but will make you feel worse longer term. H also is going to feel worse about it and your going to spin up a negative cycle where he'll want to avoid you fearing another barb, and his avoidance will make you more anxious and resentful, so you're more likely to attack. That's a death spiral as you can see that leads right down the drain.
You need to try to work on breaking that cycle by holding back on the comments. Keep telling yourself that H is not responsible for your happiness until you believe it.
Here's a suggestion: living with WAS with OP involved is painful because you badly want to control that situation and cannot. Find something you can control -- start a challenging fitness program and set a goal for yourself. Measure your progress weekly and keep a log. This has multiple benefits: (1) you will feel in control of your health, (2) you will become more attractive to H, (3) you'll meet new people and have more reasons to get out of the house.
I understand that you're doing exercise classes now -- if you're not adding goals and goal tracking, do that. It does help!
Accuray
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015