Hi, I'm not sure you should be ashamed or embarrassed to tell your husband about the situation, afterall it was YOU who was betrayed but regardless if you're with someone you love and trust you really shouldn't be feeling ashamed or embarrassed about expressing some vulnerability.
Do you think you could go a little further in telling him SOME more of your thoughts, depression and fears though? Maybe give him more of a chance to support you? Maybe he'd want to know and to be there for you?
It must be quite conflicting for you though to keep so much to yourself and undercover at times when you're with him, maybe putting on a front for him? You know at those times you probably aren't really being yourself just adding to the confusion.
The more times you can/do allow yourself to be true to yourself, authentic and genuine the more in touch you're going to be with who you are. It CAN seem pretty strange, scary, alien just letting go at times but it REALLY does matter that you're able to just be yourself and (gradually) feel comfortable just being yourself around people. Of course there will be some things that you want to keep private/things that are really personal but that should be because you choose to not because you're scared of reactions from others.
And if people judge you unfairly negatively for being who you are then those are the sorts of people you don't really need in your life.
As for the therapist though I do get that she probably really damaged your trust, afterall she was someone you felt you could trust and you probably shared a lot of personal things with her. But is it an option asking her why she betrayed you, just to make a little more sense out of it?
Otherwise if it's going to come down to finding another therapist (try not to let this experience put you off, if you need help you need help) make sure you "shop around" and ask plenty of questions before you commit to any particular therapist.
Alison

P.S. In terms of lifestyle maybe trying and experimenting with different things might spark a little more in you and bring you closer to being you as well.