I could have written your original post. At the moment I'm terrified I might have ovarian cancer because I'm getting intermittent bad pain on my lower left hand side. I know that could be down to any number of things, but I'm petrified. I've booked myself in for a private scan as I'm so worried the GP is going to think I'm a total hypochondriac as I've been in to see them so often lately. They've always been lovely, but I can't bring myself to book yet another appointment so I'm just paying for a scan as if it's nothing at least it's just my own money I've wasted and if not I'll know sooner. I'm normally a rational, level-headed type of person but I feel a bit like I'm spiralling atm.
I did CBT sessions through IAPT for a while. They did help and I felt like I had a bit more control of it, but I've only stopped going for a couple of months, which I agreed with the counsellor, and now it's out of control again and I can't help but feel like a failure if I have to go back so soon.
I have a 3 month old and my health anxiety got significantly worse when I found out I was pregnant. For me it's the fear that I might not see my baby grow up or might "leave" him. I resent it hugely as I feel I can't enjoy his babyhood as I'm constantly scared I won't be around much longer, for no real reason.
Have you always felt like this or has yours become worse recently? From speaking to people I think it is quite often the case that this kind of anxiety gets worse after having a baby as so much more is "at stake" then, if that makes sense? I can recommend IAPT. You self-refer to them and they have a variety of different types of sessions, depending what would work best for you, and it's free. I did individual sessions and found them to be very helpful. I think they do an antenatal mindfulness group session in some areas. I'm considering going in the hope it might help.
Good luck, I hope you manage to get on top of it soon. In the meantime, solidarity, it really, really sucks.