She's Not Giving Me Horizontal Funtime

Same problem most guys get to in a relationship. Sex. She doesn't want it anymore and when she give it up she's uninterested in it. Honestly, I'm getting more pleasure doing it myself. We've been together 3 years so I don't know if she's just bored of me or what but I'm annoyed by it. She still wants evrything else the same. She wants me to take her out and do all that other happy stuff that makes her happy but she won't do the stuff that makes me happy. I'm like any guy. I NEED SEX. It makes me feel better. It relieves my stress. Seriously how bad can it be for a woman? I would give anything if I was a woman and would have some guy wanting to do it every day multiple times. It's crazy. It's been a month and we're not even married!!