@QuirkyPatisserie by not talking to you and creating an atmosphere that's not going to change or go away unless it's dealt with. Clearly it must be something bothering him otherwise why say if you talk he'll get mad and maybe end the relationship. By not talking he's effectively putting stop to things already. Maybe say it's ok to have feelings or opinions but as you're planning a life together you need to be honest with each other even if it's something big, small, silly or important you need to be able to share that with each other. Try suggest ok if you don't want to talk about it right now that is fine, how about we pick a day,/time where we do so you've got time to process whatever is going on and we can do that in a safe time and place.
I don't know if you can take comfort from this butt the not talking thing can happen in relationships and friendships it's how you navigate through that is important. Just remember you're not alone.and are brave for reaching out,.