Yes, I've had this too. My DH died in mid September 2020, and I have had any number of health anxieties since. It is complicated by the fact that I had what the doctors assumed was covid in March, the after-effects of which lasted for many months, but which I largely ignored as I was coping first with DH having first fainted and broken his leg and then almost instantly receiving his terminal diagnosis. This was followed by very difficult degenerating illness (he had secondary lymphoma in his brain), then death.
The extraordinary stress of his illness and death produced all sorts of health ill effects in me. In the five months since he died I have been very anxious about possible breast cancer (painful underarm; no lump found), heart issues (raised blood pressure, but almost certainly an inaccurate monitor), diabetes, lung issues (I'm asthmatic), etc. Every headache felt like a potential brain tumour. The brain fog of bereavement felt like early-onset dementia. And then there's covid, of course.
I was working with a bereavement counsellor for some months, and she advised me early on that I was very likely to develop health anxieties given DH's illness and death, but that the stress could also make me more unwell and that I should not hesitate to discuss any symptoms with my GP. The doctors did seem to be aware of the possibilities of both increased anxiety and increased ill health following bereavement - both the GP and the asthma nurse called me spontaneously several times to check up on me.
The blood-pressure worries were last week, and as well as ordering a new monitor, I decided to take things into my own hands and start seriously improving my health. I've cut out all snacks, alcohol, puddings, etc, and am spending much more time walking. I already feel a great deal better. I've also been doing a lot of crafting, which helps.
I suffered with health anxiety a lot as a teen and young adult, but it had much improved once I became a mother. It is strange to be back there - for me, it is both the absolute knowledge that death can happen to me quite easily, and the fact that I am now all that my son has.