[19/m] in LDR with [19/F], She's become cold and unresponsive and I'm too afraid to end it

Throwaway account because she knows my reddit account* We started dating in the Fall semester and Christmas break was fine (not that its that long anyway), However we haven't been able to see each other since school let out for summer. I wanted to put things on hold because I didn't want a LDR while I'm in college (I think it’s a terrible idea) but she was persistent that it could work. The first few weeks were fine, we can’t talk lot since she works nights and I work during the day, but it wasn't bad. However, more recently she's become cold and distant. She works Sundays so Saturdays are the only days we both have off, but the last two Saturdays she didn't reply to me at all and the following Sunday she would have some excuse (busy, phone died). I know at this point everyone would scream she's cheating (and she might be) but I don't think that's it (I'm not blind, but she was cheated on in a previous relationship and it hurt her so I don't see her doing the same thing to me). Within the last week she's also started ignoring my "Love" I guess. I’ll always text her "goodnight <3" even if we don't talk that day and she usually responds to it, but for the past few days she's started ignoring it. I think that maybe she's just lost interest but if that was the case I can’t figure out why she wouldn't just end it, and I haven't ended it cause I'm afraid they're might be some other reason (she's had a rough family life, and she's living back with her parents this summer, she's also working 3 jobs). I’ve tried confronting her about it by straight up asking her what’s up but she just ignores and dodges it. We are only 6 hours apart but due to work we can’t see each other, but we had talked about doing something on the 4th of July weekend, and I brought it up again last week by asking if it was still going to happen and her response was "probably working". I figured if she didn't mention it again by the week of the 4th then I’d go ahead and end it since at that point it'd be obvious she didn't want to see me, but I'm still afraid that I might be making it out the wrong way? I'm still afraid I haven’t end it because she means so much to me, and I’ve just been holding out for when school starts back in august and we'd be back together.