I'm 24 years old and I have a brain tumour in my pituitary gland, but was one of the unlucky people who got "odd behaviour" symptoms. Lost my job and my place and was homeless for a while. Generally, was just acting wild (entered a guy's home once cause he had a sign that said "welcome" out front).

Anyway,s when I was diagnosed after getting an MRI I didn't understand that it wasn't cancerous (I'd also checked myself out of hospital against medical advice, and didn't have my parents listed as emergency contacts). I borrowed someone's phone while I was on the street (left mine, as well as a looot of other belongings in a bag and hid it in a bush cause I thought that my dad would pick it up there for some reason) and called my dad. I told him I had brain cancer and he didn't believe me because I'd "been saying a lot of weird things lately". They've since let me stay with them again and I've been here for about 5 months (they gave me 6 to stay here), but think I have schizophrenia.

I managed to access my medical records a month or two ago, and found out that I do indeed have a brain tumour, that I'm supposed to go in for surgery anytime from now to 2 years from now, but that it's not cancerous. So how do I tell my parents that I do indeed have a brain tumour (so I wasn't lying) but it isn't cancerous (so I was lying)? Don't want them to throw me out again because I'm acting "weird" (the odd behaviour stopped a few weeks before they let me stay with them again, idk why).

TLDR; told my parents I had brain cancer and they didn't believe me. turns out I have a brain tumour but not brain cancer; how do I tell them?