How sex with your partner changes

When my current boyfriend and I started going out sex was incredible and super frequent. I knew that wouldn’t last forever but what got me was how important it was to him that I finished. He couldn’t even cum until I did and we had a lot of fun with toys. That lasted for a bit over a year but now we’ve been together a year and a half and for the last 3 months or so we’ve been having sex 2 times a week (I know that’s normal) except he’s seemed annoyed when I ask to use toys (and so it doesn’t happen) and he lasts like 5 minutes tops. It doesn’t feel like he’s invested in it at all. I’m 1000% sure he isn’t unfaithful in any way, for the record. BUT I want to feel desirable, I’m only 25. I’ve tried talking to him about it but he just changes the subject. Has anyone else had this problem? Do you have any advice or thoughts? I’m getting desperate.