I'm going to explode!

My boyfriend keeps waiting every 3 days to have sex... I ask him why and he says because it feels better.... well when we have sex every 3 days he has been finishing lately in only 2 min or under.... I am now crying because I would like to of had him put in some work I was on top the past three times we had sex and he would finish quick.... I feel so used like he will only take 2 mins of his time to have sex with me and not any more then that and the past three times he hasn't put in any work during sex.... what do I do because I can't take this anymore I was hoping for him to put in alot of work tonight because I can't have sex for a week because I'm gonna have my period in a couple days..... I just wanted something that would hold me over for a week, you know what I mean? Like I'm seriously stressing because he is the one that asked for it but didn't put in any work because he says he is sore from a workout he did yesterday.... mind you I did the same exact! Cardio workout with him and I'm not complaining smh. I'm crying and stressed this has happened 3 times in a row and I don't want it to keep happening again and again.... someone please help..... at this rate of him only lasting 2 min today it was less then that I seriously was on top for like 8 strokes and he finished and mind you me and him been together for 8 years so I just think he thinks he doesn't have to put in any work anymore like I'm not worth his time .....if he can put work into a cardio workout why can't he put in work on me it's not fair at all. And he has had this whole week off from work so there is really no excuse! I tried talking to him just now and he just Falls asleep on me like he always does when I'm trying to talk to him I'm so over this right now I'm tired of having puffy eyes from not being satisfied.