My GF has a crush on someone else

Background stuff: we've only been together 9 months, we've both gone through some rough stuff throughout--from family deaths and a psych hospitalization to having to move in together very soon in our relationship or face homelessness on either of our ends. She's also in the middle of a slightly messy divorce with an abusive ex-husband. Presently: she just got laid off from her job, and can no longer afford to live here (finding a job is rough out here and you gotta pay rent somehow). Her cousin in another state offers to take her in and only charge a fraction of the rent. She lives in this state solely because she followed her ex (military guy). Her family is really tight knit and it's been rough for her being so far from them, especially since they just lost a family member (whose parents live in the state she's moving to). So she decides she can't pass it up cheap rent and being near her family, and I agree. She'll move when the lease is up. I tell her I'm not tied down here, so I'm willing to move down too. Then she gets unexpectedly laid off and now has basically a month to scrape together the money to get by and prepare to move. Suffice it to say, she's got a ton of stuff on her plate right now. So she says she wants a break to figure things out while we're in different states. Understandable. I then grieve the fact that a rug has been pulled out front from beneath us. Initially I assumed that what she needed to figure out was whether or not she still wanted to be together, so that caused a lot of tension because we live together. She told me she didn't know what to do because she feels like it's her fault that I'm so upset and she can't bare to look at me. We sorted out that she just wants space and time to get her life together and figure out where to go from here--not whether or not she wants to be with me. She says she does, that's never been the question. I accept. We talk less, we sleep in separate beds. So she's got no job, is broke, and it feels like there's a wall between us. Her coping mechanism is to play video games to forget about life for a while. She plays with these guys she's known for a long time and they're all good friends. While I'm over here being sad about her leaving she's over there laughing and having a good time till 4am. It hurts. I can feel that she wants to get out of here, which she has expressed. The boundaries of our relationship are blurred. She'll be affectionate at times, reassure me that she still loves me, even kisses me. I reciprocate for obvious reasons. The distant/affectionate thing goes back and forth for a little bit. We go to a bar one night and have a very calm conversation about the fact that she wants to break up. I accept. I want her to be happy and have what little joy she can find in this terrible situation that's been trust upon her. I notice in particular she's been having these hours long conversations with one guy in particular (I'd hear her say his name whenever I passed by her gaming in the house). It's a guy she's known since high school. She's mentioned him before, and I've been around her gaming with him. It was only every so often though. Now it's six, seven hours straight, through the night, every night for a week. She and I have never had conversations for that long. I am upset. I spend more time outside the house with friends and realize it's not the end of the world if she leaves and we never get back together. I'll move on, as you do. So I'm in the same room as her last night and tell her that it sounds like she likes this guy and I'm happy for her. She says she likes him as a friend. I tell her my observations of her behavior when she's talking to him. She admits they've had this "thing" for three years, but that nothing will ever come of it. She says it's a small crush, but it's not anything she's pursue for xyz (including that he's her ex husband's (the abusive one that cheated on her) childhood friend. She insists it doesn't change the way she feels about me, that she loves me. I go hang out with friends to clear my mind. I come back and we have a frank discussion about our relationship and whether or not she actually wants to be broken up now or when she leaves; if she wants the comfort and affection of our relationship as she goes through this rough time. I am willing to offer these things. She gets emotional (she's not the type to get emotional. She buries it instead). For once since this whole fiasco started there's some kind of life in her eyes, not the blank stare of stressed and depressed. She looks at me and tells me she loves me and she never wanted this and it's so much for her to deal with and she just can't do it all right now. After my solid week of pushing through the stages of grieving, I am at a calm place. I hold her, I tell her it's ok to not have the answers to anything right, it's okay to overwhelmed--it's an incredibly overwhelming person for someone not even twenty five. I want to help her as much as I can through this because I love and care about her. If that means being a physical comfort, a semblance of safety and stability, I can and will do it. Here's the kicker: that guy she has a crush on? He lives in the state she's moving to. TL;DR found out my gf has had a 3 year long crush on a guy she's known for a long time, but insists it doesn't mean anything and that she loves me and wants to be with me. Should I stay or should I go?