As far as trusting your H if you get back together again, I think you're putting the cart before the horse. Worrying about anything beofre it happens can create a self-fulfilling prophecy and does you no good.
The energy and effort that we put into worry is so much better spent on the things we can control.
I know it's really hard to turn the thoughts off. It's worth every effort to do so though.
If the two of you decide to put things back together, there are stategies and counselors and books and even a forum here.
