Hi, cherry! Welcome to Susan's

I had to ponder my reply to you for a bit before actually writing it down. I don't know much about crossdressing, but I do understand the fear of being cheated on.
You were hurt in the past, and hurt badly and it takes time for that fear to go away and trust to replace it. I think you're doing very well by asking about your (very understandable) fears. One suggestion I can think to give is to get to know your husband's feminine side. Go out together; have fun together. These days two women out for a drink or dinner or whatever don't automatically get assumed to be lesbian. This could help you see that she isn't going anywhere and also help you feel less left out. For example, some of the things Dani and I are looking forward to after she transitions are doing things like manicure/pedicures together, shopping, etc. You know, girly stuff

But that doesn't mean we'll abandon our current hobbies of motorcycling and history and computers. We'll just add to 'em

Please try talking to your husband about how you feel and be honest, because it's possible that your husband doesn't realize how you feel.
The only other advice I can give is to echo what TamTam said. Whose bed is your husband in at night? (BTW, that's how Dani put it to me very early on in our relationship

)
WR