AITAH for thinking my FIL is lying about a brain tumor??

My father in law is in his 40’s, single, and honestly does so much for attention. He strikes me as the “peaked in high school” type despite never actually graduating, his childhood and teenage years were spent doing/selling drugs, running from cops, fighting, etc. And he still holds that complex that he was the coolest person in town (which he still lives in to this day), I didn't meet him until he got out of prison for the second time in 2018ish. fast forward to 2023 ish, he says he has a brain tumor which causes his anger issues, chronic ear infections, health issues in general, which I fully believed at first, as would anyone, but then things just didn’t add up for me, my mother died from cancer, not brain cancer in general, but her cancer metastasized to her brain.

he says they don’t know if it’s cancer, apparently it’s also fast growing and deadly, yet he claims to have had it since 2016. Hell say he’s going to an appointment for scans and then he’ll just keep saying different things, last time it was that instead of being towards the back, it was right behind his eye, pressing on it, then it was that he had lesions on the brain, then it was that it was pressing directly onto the spinal cord, yet somehow, no hospital or doctor will accept his insurance to operate (Medicaid), i go months without hearing a word about it, and then I’ll see him post about it with tons of people giving their sympathies. None of it adds up to me, at all, i know that doctors are typically not fast at all to treat things, but if it really is as fast growing and deadly, it would not take 10 years to do something, if they suspected it were cancerous, they would rule that out with scans and biopsies (which they’ve never done a biopsy on him)

I feel like a shit person for thinking it could be a lie, but my rational thinking just has me feeling like it simply CANNOT be possible for it to be as bad as he says, yet nothing being done about it.