I can never initiate sex! it all goes downhill...

I hate initating sex, primarily because my husbands gets to it first. Yes, our libidos are different, he wants sex every day and Im happy if we have sex once a week, but we make it work. But, 9 times out of 10, if I initate sex, he goes limp after about 5 minutes!! Or never really gets it up! Hes 24 years old!!! (im 22) and he usually has some excuse like... 'its really hot in here' or 'i havent eaten anything today' or 'sorry, i just masterbated...'
When he goes limp I feel so unattractive, like I cant turn him on and I just have to wait around for HIM to get horny... feels so unfair.
I came home from work today and cleaned myself up and came out with a surprise for him. I walked in wearing a new little pair of leather panties that zip open and stillettos and threw myself at him! Im usually not so forward or bold in my choices in what I wear to bed, but I was trying a new approach... Needless to say a bad outcome occured. When he 'failed to deliver' i made him stop and started crying... Im tired of waiting around for when hes in the mood, which honestly is ever single time IM in the mood! And when he wants it, he ALWAYS delivers.

Is it normal for couples to fall out of sync sexually? What can I do to fix this?!!