Girlfriend disappeared

I'm in a long-distance relationship with a girl with bipolar II disorder, but three weeks ago she disappeared out of nowhere and hasn't been online since.

I'm very worried. Will she even be back? She's never done that to me before (we've been together for roughly three months now). She did mention that she had ghosted her previous boyfriend for a week in the past. It's been much longer than that now.

She mentioned she's very clingy, but she also stated that she moves on quickly. During a manic phase about two weeks prior before she disappeared she wanted to break up. After bombarding her with messages she came back to check how I was doing and stayed because she still had feelings for me. After that we had a great week with no mood swings on her part, which was rather unusual.

But now she's gone and I haven't heard from her nor have I seen her.

What can I do? Do I just wait and hope she'll be back? Will she be back?

As much as I think I have a good understanding of how her mind works by now (given how I struggle with OCD and depression myself, especially now), I still find it very difficult to understand her completely.

I'm also very worried she might hurt herself since she already attempted suicide some years ago.

Any insights or advice are welcome.