Maybe I’m just insecure??

So since baby has been born I was clear for intercourse 10 weeks ago. I had a caesarean. Hubby and I have been doing well adjusting, although recently; like over the last 2 weeks, He can’t seem to finish during sex. He claims that it is because he’s overweight and his heart starts racing and he gets soft which makes sense to me,(if I can’t breathe I’m not turned on I lose Interest myself!) but at the same time, he CAN usually finish when it’s him approaching me when he wants it, but if I ever make the move it like he can’t...he says That it’s just me feeling insecure for no reason and it’s him not me. But I can’t help but feel like it’s me...especially if I’m trying to be sexy and then it goes well for 5 mins or so...then he’s getting soft...idk I just feel like I don’t turn him on as much, like he has to look at me it makes him lose interest :( I’m sure it’s just because my body looks different and I’m over thinking it but still it hurts my feelings a bit!!