No sex..... ever!

Really annoyed Thant my husband and I don't have sex anymore. We have talked about it before but the conversation always ends with "we will work on it" or "we need t set time aside for us" or something close to that. We both work full time. Our son is 8months old... we have had sex maybe 3 times since I gave birth???? I feel neglected and ugly but he swears I'm beautiful or "hot". But there's no action to back it up. I feel silly just talking about it but I need some advice ladies!!!!! I've tried coming on to him..but he will say he's tired. Or act asleep. Is he cheating? Any advice will be much appreciated! Thanks.