Is my wife really stupid or what?

OK, im sooo pissed. For a month I've been asking my wife to do something small and nice for me. Idk, surprise me with a candy bar or something for Chrissakes anything really! Something to show me that you care. But the KEY IS... I WANT IT TO BE A SURPRISE OK, DON'T ASK ME JUST SURPRISE ME. So what does this girl genius do.... not a dang thing. in the past month she tried to do something for me once, but she asked me. in which im pretty sure it's not a surprise when you call and ask me if I want some damn cinnamon stix. I feel dumb enough i had to give her directions in the first place and define surprise for her. But the fact that she still hasn't done it makes me wonder... does she not like me or is she just kinda slow? She insists that she loves me and she says im always nagging him. I did nag him a month ago, i let a week go by with not a word, and she did nothing. I remind her.. then another week goes by without me saying a word and still nothing... I do not want a relationship to be like this. Im not one to voice my opinion about things, so when i do i freakin mean it. Im so sick of this idk what to do. I've talked to her nicely, Ive yelled, ive cried, ive broke it down for her this is really effecting our marriage. Shee plays like she doesn't understand when i get upset and the whole "i really do love you" crap. But idk what the hell to do about this woman... Is she stupid??????