Have you got a crisis plan?
Because within one you can fill out a section saying which treatments you feel have worked in the past and which you feel have not. This gives professionals a guide to your wishes when you are well and if you end up admitted under a section they will often act on it especially if there is a clear reason against a certain treatment i.e. you took x before and it gave you this side effect.
I'm very sorry to hear you feel you have been mistreated in the past and have had involuntary treatment used as a threat. Like i said before sectioning is rare but if you were ever sectioned there are advocacy services avaliable to help you get your voice heard about treatment and whether you should be in hospital or not.
If you have a worker I'd suggest talking through your fears with them about the possibility of being detained and your experiences as a child. They should be able to give you a clear framework of the circumstances in which you would be detained involuntarily which generally include two doctors or approved mental health proffessionals agreeing that you are suffering from “a mental disorder of a nature or degree that warrants detention in hospital for assessment or medical treatment” and that you ought to be detained in the interests of your own health or safety, or with a view to the protection of others.
More details can be found on the mental health charity Mind 's website
www.mind.org.uk. But obviously only applies to the uk hope this helped in some way and sorry to ramble,
Jen