sex question

my boyfriend has a very high sex drive, which I used too but between work, kids, being tired & birth control it isnt as high. well the past week it's back to normal & I want sex like all of the time. we had sex like 5x over the weekend which isnt normal as of late. the other night he couldn't stay hard & then we had sex last night & it was fine & he finished fast so I didnt get to finish so I wanted to go again but we didn't. so we tried to go again today & he couldn't stay hard again. I feel like maybe hes not sexually attracted to me? for as much as someone who wanted sex all of the time now I'm fully on board & now hes backing off? idk it's weird. I plan on talking about it already just waiting for the right time when kiddos aren't around. we talked a little last night & somehow his ex got brought up (I brought her up, something about one of his friends in the past) & he said hes been having like flashbacks of her & hes like well not of her specifically but things involving her. sooo... not sure if him not being able to get hard is because of him thinking of his ex, or not being physically attracted to me or maybe both? idk, hurts my feelings I guess... not really looking for much input besides from venting but I guess some input would be nice! please be nice!