When do you know to go to the mental hospital?

tw: self harm and suicide mentioned

as someone with bpd, i never know when i SHOULD go as i feel like my emotions never last long enough to warrant a stay. but then theres times when my emotions switch a lot, but mostly in a depressed state.

i know id never kill myself; however i have harmed myself before and will constantly think suicidal thoughts. i feel like being reckless and hurting myself but im not sure if that warrants a hospital visit. i know you ideally dont want to go, but i just need a break and i need to get back on my meds. i also know ill probably be fine in an hour. i have insurance so its not going to be super expensive to me.