What do you mean by "holding back your sexual desire"? It seems to me she's open to sex. If you meant having strings-free sex, then IMHO you most certainly should refrain from that. If you meant not exploring new things with her, then that can probably be worked out: there are positions other than on top and from the back, she might be interested in some of them. Just keep it fun and light and make sure she does not feel degraded if that concerns her.
But the question is, do you want to remain in a relationship with her? It looks to me that you guys are pretty different: I mean she doesn't even want to try different positions and you're craving strings-free sex? There's quite a gap in your approaches to sex there!
And she gets mad about you going out with friends??? That's not a good sign! She's probably jealous that you meet other girls at clubs, or just simply jealous of your friends, and that's not a healthy reaction. She needs to give you some space, and have some of her own too. Does she have some friends with whom she can hang out? She should. But anyway, you can't stop seeing your friends because of her, nomatter what type of people they are. (I assume here you're not giving your friends way more time than to you gf, but only you can judge that)
You should take some time to re-assess your relationship, and whether it's really what you've bargained for, or whether it still suits your needs.
"But I, being poor, have only my dreams;
I have spread my dreams under your feet,
Tread softly because you tread on my dreams"
- WB Yeats