<human>: It's a long-term LDR because she's in school. We've been together almost a decade. 

Today, I was supposed to take a flight to visit her this weekend (it's her birthday weekend) that I booked months in advance. But I thought it was tomorrow because I'm fucking irresponsibly stupid and don't stay on top of things. It's not that I don't give a fuck, but for the last few months, I actually told myself the flight was tomorrow. Marked on my calendar flight on the 21st. I don't even know why, it obviously says 20th on my e-ticket. 

I call the Airlines, and they tell me I have to pay 400% of my original ticket value just for a one-way last minute flight. I don't have the funds to do it. I check a bunch of travel sites and the cheapest I can get one-way is still huge compared to what I originally paid. 

I called her to tell her I fucked up, she cries but after a while she fakes being okay and tells me she loves me and not to worry and things are okay and to just text her and Skype with her the entire weekend.  She's been looking forward to me visiting her, since we both really don't know when we both will have the time to visit each other again for a really long while. I know she's been planning this weekend for a fucking long time and she's been telling me almost daily how excited she is I'm coming. We used to be around each other 24/7 but due to diff post-grad programs we had to go to diff places in the world. 

It ended there, I know she's really hurt and faking it and because she loves me she's gonna pretend like it's fine. I don't have the money to fix this problem, and there's nothing I can do and I feel really down. There's a bunch of feelings I am feeling right now but I guess to summarize it I feel extremely down.

Summarize the given text in a few sentences.
<bot>: I didn't stay on top of things, missed a flight in a LDR, gf says she's ok but obviously it's a real shit situation. I feel really down. Not sure what to do or think.