I don't understand

Well my wife and I have been married for like 7 yrs and so far the past two months it's bad. It's about sex. Evertime we have sex she ends up being dry fast and I get upset. She cm but after that she sets up.. so told her I can go down on her and she said no she doesn't like that so I tell her well ... I'll buy some lube and she got upset with me and said no too .... Idk if I'm right to get mad because I haven't cm in her for two months and I don't like to j off to porn I thinks it's wrong. So I just deal with the frustration. So two nights ago I tried romance and messaging her and she lets me and after all that she tells me I'm not wet just to let you know so I decided to try go down on her and she stop me and nooo I told you I don't like that!! So I let it go but idk what I'm doing wrong and alot of negative things running in my head but I tried to let it go but it's hard too. Idk if I'm over reacting but it's been along time I have cm and I want to so bad so please help me and what's your opinion thank-you