yo i vibe w everything you talked about. i know this doesn't like, help you a lot, but you aren't alone. i used to be so clingy towards 2 of my friends. kind of ruined the friendship but i chose not to stop myself.. 😬
it's better to be honest about your feelings w your friend rather than hide them. i wish i could say everything would work out, but i can't promise you that. sometimes people can't handle the truth, and sometimes it does ruin relationships. but that's OKAY! not every friendship will work out, and when you're in a rut, it just makes it that much harder. but if they're meant to be in your life, they'll still be there at the end of the day.
i hope that the mental institution helps you feel better, but just remember that you aren't weird or a burden or anything like that. sometimes we have tendencies that can't be controlled on our own. and the first step to getting better is admitting that something isn't right— the next one is actually getting help. so you're doing what you can, and i am proud of you for trying to get back on track.