I'm I the problem?

I’ve noticed a drastic change in my boyfriend’s libido lately, and I’m trying to understand what’s going on. We used to have a healthy intimate life, but now it feels like something’s shifted, and I can’t ignore the timing.

Updates
7 mo
I have gained weight recently due to health problems, and I can't help but think that's contributing to his lack of interest. He can't even keep it up sometimes and we have to stop. He's only 36. I tried getting on top recently and it ended embarrassingly, and he just got this look on this face like he was in pain and uncomfortable and wasn't even hard anyway. I was quite humiliated. 😟
I'm I the problem?
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