Will, I'm so sorry to hear about your health anxiety. I'd had little twinges of it in the past, but nothing like I've been experiencing lately. It's a shock how painful and paralyzing it is - I'm really sorry you go through that.

One thing I read recently that's been helping is that managing health anxiety is not about finding the diagnosis of the health trouble you feel certain you're having, but about reducing the anxiety. For some reason that really touched me. It made me feel like I might be capable of doing that; it made the issue about anxiety (manageable) rather than about dying (ultimately not manageable). When I don't feel well but I'm not experiencing such anxiety, I just take normal, sane steps towards finding out what's wrong and getting myself better. What makes those moments different from this moment is not necessarily that I'm more sick, but that I'm more anxious.

It's helping to talk about it too. I hope it helps you.