It comes down to one question, who owns my body? In a free society, the answer has to be, no one but you. On that principle, the state has no business interfering in a private matter....unless Conservative now want all citizens to be wards of the state.
I don't want to live.
Ok
I want you to kill me.
No.
You have a right to the first, you have no right to the second. You are asking me to take ownership of your life because only the one who owns it can end it. You may not do that. Your ownership is nontransferable. You can not sell yourself into slavery. You can not hand your life over to someone else.
This is from a legal standpoint. Morally is quite another thing.