Why does it seem like my girlfriend wants nothing to do with me?

I’ll keep this somewhat :\ short and skip a lot of the deeper background;
-I’m in a LDR with my girlfriend who lives a few states away
-Mid October she had gotten very sick and seemed very distant since; blaming it on the sickness when I inquired about it
-A couple weeks ago I bought plane tickets to go see her again over the holidays
-Thanksgiving night she said I never talk anymore or care about her despite my many attempts to talk to her only to be more secretive, cold and distant. (So I figured I should give her some space until she wants to open up again)
-Since she had added me on Facebook she detagged the photos of us I had uploaded and steadily has been decreasing the available info on her page, and seems to get rid of anything that might lead one to think she’s with me.
-Recently she’s been gone quite a bit working on a ‘project’ that she doesn’t want to tell me much about with an ex of hers who had threatened her while I was visiting her in the Summer (I guess saying sorry means best buddies immediately? – also when she did tell me this she made it a point to say it’s a purely platonic relationship and she didn’t want me to think she was screwing around)

Anyway; what’s drawing me to pose this question is- today I came home and she forgot to clear her recent activity or something I guess (I honestly know pretty much nothing of how Facebook works) and saw she commented on a trip invite saying she’d ‘come in a heartbeat if she didn’t leave ******’ with ****** being the date I would arrive there. It made me feel a bit hurt because what’s the harm in just saying ‘Wish I could go but I have a friend/my boyfriend coming to visit then’. I kind of want to bring it up and appologize for getting in the way of something she’d like to do but then I could seem snoopy and clingy. Which I will honestly admit to being a bit of the latter when it comes to things like this.

I’m not really sure what to think, I feel bad for questioning it but at the same time it’s getting kind of old to feel like a ‘fair weather boyfriend’ I’d really appreciate a female’s input on the situation and just general thoughts or suggestions on what to do or how to handle it.

Thank you for dealing with my insecurities :D

and to those who may remember my older questions; yes this is the same girl