Hi. I often experience suicidal ideation, but don't think I would ever actually do it, unless something catastrophic happened in my life, such as if I found myself homeless. I'm on disability and survive on a meager income.
I've talked to my therapists in the past and my current psychiatrist about my suicidal ideation. They are professionals and know that that does not mean you are currently suicidal. But still, to prevent being locked up, I always add that I have no current plans or intentions to commit suicide.
What worries me is that you are seeing a school counselor who may not know the difference between suicidal ideation and actually being suicidal. So, if you don't want to be institutionalized against your will, I would make it very clear that you are not currently suicidal.
But after stating that, going on to talk about your suicidal ideation could help you to deal with it better by having someone to talk it through with. So I would suggest considering bringing it up so you can finally get some help for these issues. You shouldn't be locked up if you say you're not currently suicidal...
I'm sorry you're going through this and wish you the best of luck! I can relate.