Unfortunately, lots of GPs don't understand the impact of discontinuing them cold turkey. It sucks. I would attribute a lot of what's going on to that. It does all kinds of crappy stuff to your body.
I know how you're feeling. During my last "episode"…I couldn't sleep, couldn't eat, woke up several times a night, it was awful…had all kinds of symptoms and was convinced I was dying. I'm back on Celexa and staying there. I feel a lot better but still have to actively think logically to prevent the panic from taking back over.