How to I tell my roommate I want to move out

So this is a complicated situation. My roommate and I just resigned our lease for another year. However it’s under her name and I’m listed as an occupant instead of a tenant. The problem is, there’s been a lot of tension between us lately. To my knowledge there’s no reason but a few examples is: she never speaks to me anymore, doesn’t say hi unless I say it first, when I try hold a conversation she’ll give one word answers and won’t make eye contact, also if I’m outside in the kitchen she’ll stay in her room and if I come home and she’s in the kitchen, as soon as she sees me she’ll take whatever she was doing and move back to her room. So obviously there’s a problem cause this is a recent development. I’ve tried asking her many times if there’s an issue (and if there is and I’ve done something to annoy her, she must let me know so I can stop) but every time I ask she always says no so I can’t do much more. At this point it’s pissing me off now to cause she won’t communicate with me and I can’t live like this so I want to move out. But like I said we already signed for another year and even tho I’m an occupant so I could move out whenever, I don’t want to be an asshole and just…like…leave ya know? And leave her to scramble with rent and finding another roommate. My problem is I am scared of confronting people (I’m trying to work on not being such a pushover) and so does anyone have any advice on how to go about this?:/