Lots of nurses experience panic attacks. I've had them, I know several who've had them. *rolls eyes* (I am a nurse)

I don't know that I would beat yourself up about this too much. But I feel like I'm missing part of the story. When you talked to her on chat and said you'd be gone for a while, did she know you were unfriending her? If so, unfriending isn't a usual practice for people who are going to be off social media--unless you've blocked her, she can probably still see your account in her "suggested friends" list. I'm only asking because if she's anything like my close friends and some family, whom I'm ashamed to say I used to go through bouts of unfriending with, she doesn't think too much of the behavior because she's your friend. If she knows you at all and has been privy to your struggles, I doubt it comes as a surprise. Hopefully that doesn't sound harsh; it took me a while to realize my friends knew I was mercurial and were my friends because they rolled with the punches.

I think it may benefit you to work on the jealousy issues a bit before trying to add this person back. I have some issues with the same, and I don't go on social media much because I know it doesn't truly represent the entirety of a person. And it is just a trigger for me at times. (and, frankly, it's boring) If you want this person back in your life, send her an honest message. It might not work, but people appreciate the honesty. Otherwise, perhaps let the issue fall to the wayside so you can work on the root of the matter.