My Fear of Getting Ill with My Chronic Illness

my biggest fear is: I'll get seriously I'll with cancer, tumor, heart attack or other less life threatening things that become bad when left un-treated like appendicitis. but I won't pick up any symptoms because of my chronic illness which causes pain, nausea and a multitude of other symptoms. I'm also on a lot of pain meds, including gabapentin which numbs my nerves so I feel less pain overall and I'm so scared I'll get I'll. the main one ATM is appendicitis, I'm so scared I have it and it causes me panic attacks and I want to go to a doctor because I have literally all the symptoms, bellybutton central abdominal pain (though its more of a dull ache) excessive thirst, loss of appetite, nausea and vomiting. but once again I get these regularly anyway, just usually not all at once. its been like this for about a week and I've told no one because they all tell me the same, I'm overthinking it. but I'm so fucking scared.