Hi. First I'm wondering....are you still in contact with her (Facebook, email, text, phone, face to face - it all counts)? I'm thinking you must be since you know she's dating.....how often are you in contact? How long since the last time you were in contact? When's the last time you checked on her (whether or or you spoke to her)?

"I haven't been in contact, last time we saw/ talked was before thanksgiving."
If you talked/saw each other before Thanksgiving, you ARE still in contact!  Why did you talk/see each other?  How often does this occur?

"We are not fb friends, all of a sudden I was unblocked."
How did you know you were "suddenly unblocked"?

Good to know - way better than what I was afraid of (you checking FB to see if you could access her page, frequent contact, etc.). First, there are some steps you can take to avoid contact / hearing updates about her. Now that you know FB is a possibility, get in there and block her. Having her pop up as a suggested friend, finding her on mutual friend's walls, perhaps having her send a message or friend request won't help you get where you need to be. Next, tell your mutual friends that you want them to avoid bringing her up in front of you. If they understand you're having trouble getting over her (or if you prefer, tell them you find yourself thinking about her *again* and need their indulgence in helping you get past that. Another thing is contact -- be good to yourself and avoid all contact. If you have something to deliver to and you have reason to expect she'll be there, don't go -- have someone else make the delivery for you, arrange to drop it off somewhere else, have them come to you or whatever you need to do, but don't put yourself in her path. Also, if you come across her unexpectedly, avoid her if you can; stay out of sight, leave, whatever you need to do, but avoid even visual contact. What are you doing to keep your mind occupied/averted? When thoughts of her come in, do you redirect? If not, start! Keeping busy is important too. Get out and do things with friends, take a class, join a gym, volunteer...whatever appeals to you. Look at this as a project and get to work at getting yourself through it. I know of a good article on the subject that I can send you by private message if you like (this site doesn't allow sharing links and articles).