Ugh. But where is she gonna go? That's the biggest thing stopping me right now. I'm not trying to be all emo or anything here, but I feel like I'm throwing her out on the street.
Not wanting to sound heartless here and I know you are a caring guy which is why you are struggling with this but where she goes has nothing to do with you. Maybe it is what she needs to get a kick up the butt and stop depending on you and controlling your life. When you break it to her tell her you care deeply about her and understand her situation re having nowhere to go and offer to assist her with finding something. She will have to stand on her own two feet and that means getting a job, finding a flatshare, making friends etc. Staying with someone just because they have nowhere else to go is not fair on either of you. You are just delaying the inevitable and in the meantime resentment will build and things will just get worse. It is going to be a shitfight breaking up and she will be crushed but what is your alternative?
Some people are drains and some are radiators... Keep clear of the drains and hug the radiators!