I've seen things similar to this happen before. Not that I have any definitive solution to this, but you have all my sympathy and empathy.
There's a reason people make a whole research field. They seem complicated and random to most of us. Those who don't think so are probably wrong.
She might be sincere. We all make mistakes, some worse than others. She might realize it and regret, even if this doesn't look like it. For now, at least.
She might just as well be completely lost. Maybe she'll come back, maybe she won't.
All in all, she hurt you and probably hurt herself as well. This is not an excuse for anything you may do to each other, but it always gives reasons.
Suit yourself, follow your instincts. If you want some time apart, take your chance. Same goes if you want to wait for her or completely run away from what ails you.
Just don't force yourself to do anything you don't want to. Don't blindly do what others tell you to, including what I'm saying, haha.
Don't have too much rest or stay indoors for too long, it's a vicious circle. Depression is more easily achievable than one thinks.
You like your Bug, then plan a trip. Litterally changing your scenery will let you put things in perspective. There's probably a Beetle owner's club nearby if you haven't joined one already.
For lack of making best friends, at least you'll find something in common with other people. Kinda like this very forum, in fact.
Whatever you decide to do, remember that when there's life, there's hope and, as we froggies say, hope makes one live.
Take care and here, have a smile :