you don't need someone to "give" you the right to suicide. Humans are naturally born with this right.
They aren't gonna throw your corpse in jail for killing yourself.
As far as the Christians, would you be pissed if someone told you that if you put your hand on a hot flame you'll get burned? Cause that's all they're doing. No need to hate over it.
Even if you have cancer, if you put your hand on a burning coal you'll get burned. Even if you have cancer, if you step off a building you will splatter and hit the ground. The law of gravity does not end just because you're sick.
The same applies to moral laws, such as the spiritual law that dictates you should respect your own life. Disbelieving in something does not stop it from existing.