Should doctors be allowed to help critically ill patients commit suicide?

I think that doctors have the CONSENT to help someone end their life, if they want because if they are going threw so much pain and they just want it to stop, then they should be able to speak for themselves as humans what they want. Even if it is against the doctors CRITERIA. Like if the person thinks that they have had a good life then there is no point for it to go bad because of an illness. But if the person just wants to be suicidal then doctors shouldn't help people with that. But people should have the right to tell someone they cant end their life because there is a chance they will survive. So i think doctors should help patients end their life as long as it is a legitimate reason.