[Question] Illness anxiety disorder: how to become more rational?

Disclaimer: When I think about dying I mostly think about cancer (I don’t know much about other diseases). In the following, I’ll be refering to “cancer” to point at deadly diseases where early detection is crucial.

[Epistemic status: thinking out loud; trying to debug my irrational mind.]

Situation I strongly believe that I have final stage cancer. When I touch my pectoral muscles, I can feel lumps. I have been suffering unbearable anxiety for the past one year and a haf or so, feeling that something very wrong is happening.

Medical Evidence One year ago, a cardiologist told me my heart was fine and didn’t see anything from ultrasound. In the past two months, I checked two GPs. The first one said “it’s probably just muscular”. The second one (extremely talented, known as Dr. House) recommended additional ultrasound/​computed tomography.

Internal Evidence It feels real. It hurts. It’s cumbersome. It affects the left part of my chest and my left arm. Whenever I touch it I can feel that my left chest is of a very different consistency compared to my right one.

What happens I can’t do any meaningful work. My mind is immersed in daily pain and the possibility of a final stage cancer. When I think about doing the additional tests, I’m TERRIFIED by the idea of having a doctor tell me “you have 4 months left”. Yesterday, I managed to make an appointment for an ultrasound. However, I’m broke, and it turns out that the particular doctor is really expensive and has really bad reputation online (3/​5 google reviews) so I ended up canceling it this morning. Also, I spend a lot of time in self-loathing, insulting myself for not having done any medical exams sooner, when the disease was “not yet deadly”.

What I tell myself when I’m trying to be more rational I check the actual statistics of having some kind of cancer in my left chest. For males, breast cancer is 100 times less likely than females. I’m in my 20s, so the probability of having a cancer is smaller than for old people. When I look at actual symptoms of breast cancer, I have none. Most importantly, after checking actual cancer statistics, there’s the chance of having a thing and still surviving (probability depends on the type of cancer and stage).

Also, I’ve been feeling pain for about one year and a half. So if it was something like a cancer, the actual pain would only appear at end, and wouldn’t keep on going for a year. Plus, Dr. House not being impressed by my lumps is some evidence that they are not so impressive. And when I touch my right chest, I can also feel weird things when I search enough. The pain in the left chest could be something a psychosomatic phenomenon (at least to some degree).

What I actually tell myself I’m dead. The lumps are actually there. Look, when you press here you can feel this really strange thing. It’s gross. It’s getting worse and worse. It’s very large. Oh my god it’s a final stage cancer. I won’t survive. I’m such a piece of shit for not having gone to a doctor. It’s been over a year. Fuck. I should be doing more tests. But I’m broke. And the outcome of doing more tests will be one of the following:

1. The doctors are not able to identify my disease and I’ll keep being in pain /​ anxious /​ dying.

2. They identify something and tell me “you have four months to live”.

What I’m asking you I need help. I know most of what I think doesn’t make sense, but it FEELS very real. It’s like having some really strong internal evidence that something bad is happening. I know that doing more tests if the way to go. But because it takes 2-3 weeks to get an appointement for a good GP, so there’s always the bias of trying to avoid to think about death and procrastinating the appointment. And there’s this additional cost of having to borrow money to do any test to begin with, which is painful to think about.

In short It feels like I’m Pascal Mugging myself when thinking about death. But I’m also the complete opposite of a hypochodriac that would go see a ton of doctor because he is in distress. I FEAR going to a doctor because I’m afraid he will either not find anything or tell me I’m dead. It’s unbearable, so I need to debug my brain.

What should I tell myself to become more rational?