Hey Eleny!
I don't think my answer will be very helpful, but I'm just here to tell you that I completely understand how you are feeling.
I've gone through this so many times.. My boyfriend always tells me "you can't see someone's emotions or intentions through a text" and, although I realize he IS kind of right, I still do give a text a different interpretation when there is one heart less than usual, or no upper case, or no smiley and so on, and I'm pretty sure you do the same.
I really hope that you worked things out by now, and if I have to tell you one thing, just please always remember that if something makes you feel hurt, then it is important.
No matter how strange it may seem, your reaction to something is valid, and no, you're not neurotic, you just suffer from BPD and unfortunately, it's normal for you to feel this way sometimes-so don't worry. You're not neurotic.

Sending you lots of hugs, and good luck!!

Sorry for my bad English, I'm Italian