Am I wrong to speak up about our life?

Lately the with my boyfriend has been on the wain - he has been complaining of tiredness etc the last few months - but I can't help but think at times he just can't be bothered. He has always been pretty selfish in bed and we only ever have when HE wants it. Lately this has been once a week which I find frustrating - sometimes it can be more, sometimes less. I guess it's the controlling nature of it and his lack of compromise that frustrates me. Anyway I have told him I am not happy about it and asked him what the deal is. However I feel guilty for pressuring him now like I am some sort of nymph. I have a right to be happy in all areas of the relationship don't I?