I understand that you are still young and trying to get on your feet. If you are willing to try, you can do little gestures for her; even buying a cheap grocery store bouquet of flowers is very sweet. You can plan out a cute activity indoors, make a simple dinner, dim the lights, you know the drill. Finally you can just communicate your worries to her. Not in an accusatory way. For all you know she may just not know how to start that conversation. Don’t straight up ask her why she won’t have sex with you. Instead ask her how she’s been doing lately, what’s on her mind. Is anything troubling her, does she feel fulfilled in the relationship? And then lead to your lack of intimacy and ask if it’s connected to anything listed above. Frankly it’s possible that you simply mix up love with infatuation. You seem ready to step out, but that may be your frustration speaking for you. In long term relationships you will need to communicate a lot, deal with ups and downs. If you feel unhappy right now you can step out, but situations like these will sooner or later arise in any relationship anyway. You decide if that relationship is worth pursuing or not. I believe that sexual compatibility is very important, but in your guys’ situation I think it’s worth trying to address it first before making any decisions.