Is it bad to break up with your live in girlfriend just because she doesnt have sex with you?

Have been living together for about 8 months. She does the 'standard' partner stuff: Keeps a clean house, cooks sometimes, is nice mostly. Just no sex. Oral maybe once a week if I am lucky, but rarely ever actual intercourse. Mainly I want to know if it is healthy for me to place so much of an emphasis on sex in general and if so then what should I do because I feel like I have tried everything. To be clear: we had sex within 2 weeks of dating and moved in together after 6. After the 1st month sex started slowing down and she said "It will pick up after we move in, because I dont like your roommates." So after 6 months we move in together and it never picks back up. She is 20 and I am 25. I just dont get it and am at a loss.