Yes.
Twice I have been in what I would describe as being in the waiting room of suicide, really dark place to be and not particularly fun. Speaking to a therapist was one of the best things I ever did, even though there was and still is a real stigma about it (so much so that only my wife and this forum knows that I have been to such a place).
I think suicide can be a normal thought process regarding ones own morality, although it is very easy to spiral out of control. I called the NHS in my second "episode" as I was working next door to a motorway and basically had thoughts about whether jumping down would be a realistic option for me, for all the shit they get for my mental health they were brilliant.
I don't think anyone with thoughts like me/you are ever "cured" but you can do enough to keep them at bay. Happiness and sadness are healthy feelings, in the right moderation.