High tension, low intimacy

Please dismiss any grammatical errors or politically incorrect ideas, I'm typing this drunk off my ass and I am desperate for some input.

For the past year in my marriage I have been very sexually frustrated. I often feel that sex is always on my wife's terms and she calls all the shots. On the rare occasion that I get any, I initiate the foreplay and it only lasts as long as my wife decides. Once she is all "warmed up" she always decides she wants to ride me in the cowgirl position. Times I have insisted on more foreplay have resulted in argument, so I have pretty much given up on that. After she gets on top, she lasts maybe 2-3 minutes before cumming and then I flip her into missionary. I'd like to give it to her doggystyle but she says it hurts. I am lucky if I can manage to get off before she dries up. More often than not, I get overstimulated because she doesn't stay wet and then I have to deal with her insecurities when I don't get off. Otherwise, she thinks it takes me a long time to get off when in fact the whole ordeal doesn't even last 30 minutes. I vividly remember having sex that lasted 2-3 hours in the beginning of our relationship as well as with previous women in my life. That's about how long it takes me to really have a "complete experience".

We are having sex maybe once a week/2 weeks and I have a need to get off about once a day. There are other strains in the relationship but I personally feel that if I can meet my sexual needs I'd be more motivated to work toward other goals and reach common ground. I've tried to explain that to her.

I've explicitly outlined my sexual desires for her- that I'd like to have more oral sex and extended foreplay. I have also mentioned that I feel it's unfair that we usually end up in the same position, which happens to be HER favorite. It just doesn't seem to make much of a difference.

At this point I am desperate enough to even watch porn and masturbate in her presence to get the point across. I've lost a lot of confidence in myself to resolve the issue and it's time to gather some outside points of view. What advice do you have for me?