Accepting my bi husband

I thought I had as soon as he told me before we got married 5 years ago. Never was an issue for me. Hes never been with a man so we've definitely experminted with butt stuff through out the years and he even crossed dressed off and on at home for a little while. It all stopped for awhile mostly but he would tell me he did stuff to himself during masterbation which ya know masterbation is healthy so ok. Now he's wanting us to do more and the other night I used a toy on him and his eyes are rolling back and he has intense orgasms which at the time was hot and now he wants to get a strap on that shoots out cum so he can feel what that feels like. I was completely fine with everything until I started having nightmares after our session the other night, it was him cheating on me with a guy and he didn't even care that I wasn't going to put up with it and leaving. Yes it was just a dream but I can't tell you how heartbroken I woke up feeling and it has stuck with me for days! And then I had another one this time about a girl that looked like a guy. I did tell him about it and he reassured me that will never happen that he loves me and I know it's dumb to feel like this over a dream but its made it harder to think about him enjoying it so much and wanting to do more. I feel like it's mostly just insecurity cause I don't have a penis obviously and a part of him likes penis and that's not something that can ever change. Anyone else have a bi spouse and how do you get over the insecurities?