Hey love,
A hospital is designed to keep you safe - and thus, no self harm. However, it's not as difficult as you sound because it's not going "cold turkey" as such. You're in an optimal place for your recovery and there is support to help you through it, so any urges you have can be addressed with the trained staff who can help you work through it. Hopefully, it will teach you some new techniques.
I'm very please to hear you're taking such a positive step in getting support; I hope it works out for you. As this is your first visit -or it sounds it- I suggest you read some of these things on "
Psychiatric Hospitals" to give yourself some advice while you are the, and make it as useful as possible for you.
Best wishes!
Aimee xo