Ok so I recently got diagnosed with BPD and everything makes much more sense. Anyway me and a friend got into it a bit which resulted in us not talking for a week. Or her seemingly ignoring me after the couple texts I sent her of me apologizing profusely like "omg im soooo sorry I don't want you to be mad at me. I understand if you don't wanna be friends anymore etc., etc."
So today she finally texted me and told me that she wasn't mad at me and that she just had a lot going on. We ended up talking, I brought up my BPD and she told me basically that no matter what we get into that I could always come to her no matter what and she'd be there to offer her love and support and other mushy stuff lol. And it's like I know she means it, but I know I'll forget it and my subconscious will make me wonder if she really meant it by tomorrow and I'll fall into a deep depression by Wednesday likeee....?
I feel like this ungrateful person just thinking in black and white all the time when I literally just can't fathom people caring for me for such prolonged periods of time. 
All week I felt abandoned and kept thinking "omg what if she never messages me again" "of course she doesn't wanna be your friend, she's five years older than you" "shes at a party on Snapchat, what makes you think she wants to talk to you" and just UGH.
Do y'all have *any* advice on what to do in those moments? Like how to at least lessen that feeling? It hurts so much. 
PS. I'm not on any medication (yet) btw. 