should i tell my friends and family that i have cancer?

i was diagnosed with stage 4 lymphoma a week ago and i dont know if i should tell anyone ,the only ones i told were my parents and they are telling me i should tell my friends and other family members but i dont want to for a bunch of reasons the biggest is i hate pity ever since i was a kid i hated when someone looked at me with pity and the other reason is i am afraid they are gonna change how they treat me (pity)

can you guys tell me did you ever regret telling anyone?

and what is your opinions ?