Wow, Smills, you've not only received great advice, you've written very clearly and thoughtfully about your situation.... why not add writing to your list of things to develop for yourself?
I very much agree that working on your own self is the only answer here. If I were you, I'd make a big effort to drop all your thoughts which analyze your husband or your relationship, and concentrate on your own happiness and personal development. Why? Because your own self is the only thing you can possibly change and be responsible for.
I think many women believe that marriage is more than it is in reality. We are raised with a silly belief that if we marry, our lives will suddenly become perfect and all our problems will disappear. We all learn, if we marry, that nothing could be further from the truth! An intimate relationship makes things more complicated, not necessarily better.
We never find that "perfect" storybook marriage where we live happily ever after with no effort on our own parts. A bit disappointing, but it also frees you to be yourself, and reminds you that only your own life and your own actions are under your control, married or not.
As for things to actually do, I'd personally visit your local library and look up books by Albert Ellis on RET or REBT (Rational Emotive Therapy or Rational Emotive Behavior Therapy). This therapy focuses entirely on your own thoughts and how they affect your actions and your life.
If you can learn to stop worrying and putting yourself down (and it's hard to do), you can free yourself in ways you never dreamed of before. I like this therapy because you can start working it Today, and actually feel a bit of difference. It takes a lot of work and persistence, but it's something you can do on your own, with no help from anyone, and that's very empowering. You realize your own strength has always been there, inside yourself, just waiting for you to develop it and make use of it in your life.
Exercise, classes, a part-time job, crafts, needlework, hobbies, are all great things you can do & have already been suggested. Meditation is also very good to learn (books by the Dalai Lama are my favorite), to get some control over one's sometimes scattered thoughts.
A new therapist may be in order, or possibly just dropping this therapist... if this person isn't helping you, don't pay them!
Have you tried the book, "Fighting For Your Marriage?" This has a great technique called the "Speaker-Listener Technique" you can use to talk to your husband, which just communicates each of your thoughts without doing anything to change those thoughts. Listening to one another without judgment can make a huge difference.
I get the impression you'll be fine, Smills. You're just at a difficult spot in your life. Things will get better! Chin up! We're all rooting for you!
P.S. - And congratulations on your succesful Rehab experience. Pat yourself on the back, OK? You did a really difficult thing, which not everyone can do. Having met that challenge, set yourself some more challenges! Big hugs to you.