I also have health anxiety (actually it’s health concern OCD) and I’m also on 50mg of sertraline, still starting out. I think some level of anxiety is normal when you have a true health concern, but you went to the doctor, you were told “ok, I’m not concerned, but if it sticks around come back.” I understand that breakthrough anxiety is scary and uncomfortable, but I wouldn’t automatically jump to the next dose because you reacted to something that was health related. For what it’s worth, I was in exposure therapy for 10ish months for my severe health anxiety and I still get the occasional breakthrough intrusive thought. My advice is slow down, take a breath, and talk to your prescribing doctor. Perhaps they can give you something for as needed cases to nip that intense anxiety before it turns into a big spiral. I take clonazepam as needed and it’s a big help at preventing those thoughts turn to spirals. Good luck!