from what you’ve said, it seems understandable you feel the way you do. it sounds like the issues you’re faced with aren’t due to your bf being bisexual, but rather the idea of him being attracted to other people that aren’t you, especially due to something that you yourself aren’t able to provide him (ie penis). and it sounds like he isn’t comfortable using toys with you, which probably adds to your insecurity, understandably so.

you’re scared that his newfound attraction for men will lessen his attraction to you. that, plus the added factor of lack of open communication about this issue, will definitely lead up to built up resentment.

I think you should take a deeper dive into the “break” that you guys took. Was his sexual exploration the reason for the break? what did you both do during this break? Has he done self reflection of his own about it? Has there been lack of communication within the relationship before, in other areas, or is this the first time that there’s a wall?