I think you are entitled to do whatever you want. It is your life. Cancer, depression, any other illness or conditions could be the reasons for somebody to want to end his/her life and nobody should judge that person. I barely know why I should stay in this world one more day, how could I speak about other people's wishes and motivations? We all have the bad habit of judging other people. We all are too opinionated. And this harms ourselves first, because in turn we are afraid of others' judgement including God's judgement or our conscience's judgement, which is the internalization of our first significant others' judgement and society values.
We should free ourselves. We should own ourselves and do not be afraid.
Having said that, I think that also it is true that life in us wants to live. There should be a drive in us that makes us want to stay alive. And if the drive does not work, I mean, if we are not driven to life by this internal force, we are not well. Naturally we should feel we want to stay alive
But we should not judge ourselves or others if they do not want to stay alive. Depression is a mental health condition, it is not a matter of choice.
And this is personal, I do not think God (if there is one) judges people.