Are there cases when people don't get over certain relationships?

I'm asking primarily because I worry about my ex. One month after a breakup and all things considered, I think I'm doing fine. However, I worry about her. Even though we didn't function well, we had an intense, firey and passionate relationship although a lot of that can be attributed to her personality, especially the intense part. She was like a rotweiler when he grabs something, there's no letting go.
There were times when she would tell me stuff like she couldn't be happy without me, there were some suicide threats as well and not in a manipulative way, believe me. I do understand she isn't exactly a stable person although I sympathized. All things considered, it's a wonder she's still alive considerng some things she's been through. Let's just put it this way, take 5 of each woman's worst fears, she's been through 2, almost 3.
It sucks hurting a person that's been through so much but again if it doesn't work, it doesn't.

Anyway, she wants to love and be loved. Simple. Do you think she''ll be able to move on or do people sometimes don't get over some people? Generally, do we always get over or is itmsometimes impossible no matter how much time passes, how many people we hook up later etc?

I believe the only reason why you are worried about it right now, is because you are not over it. You can feel like you are until you are blue in the face, but once you start asking these questions, it becomes obvious that it is still on your mind, which means you are not done with it yourself.

I would say that it is very rare where someone will never get over a breakup, and I would say that eventually you both will move on...maybe not completely forget, but will again find someone or something new to explore.

Of course I'm not over it yet. I just think I'm doing fine. There are moments of sadness every day but all things considered, breakups are rough so it does come with the territory. I think i'm doing fine. I am however very worried about her.

I can imagine she is going through a rough time and can only hope that she is not choosing a destructive way to express her emotions. I don't know her, and I know very little of the situation, but from my experience with people and other situations time does seem to heal all wounds and I hope that is the case for the both of you.

She'll be fine.