Bf ignored my naked pics

Anon
My bf and I are going on 2 years. I love him more than anything. But lately I feel like our sex life is dwindling. He won't really respond to my dirty texts with another dirty text. And last night I sent him a nude from the shower and I got no response at all. It's starting to make me feel like I'm ugly? I've mentioned it to him and he says he's just getting old (he's 33!) is it me? Maybe he's not into me? I'm afraid to really sit down and talk to him bc he has a habit of taking serious offense to my feelings and he'll start getting defensive and pissed bc I'm "attacking" and trust me I try SO HARD NOT TO. I use terms like "I feel" and never try to blame. What do I do? I'm so hurt I'm crying. I feel like he doesn't sexually desire me anymore.