Hello aedgerle: This appears to be just your second post, here on PC. So I'll take this opportunity to say... welcome to PsychCentral!

I hope you find the time you spend here to be of benefit.

May I suggest you introduce yourself over on PC's New Member Introductions forum? Here's a link:
https://forums.psychcentral.com/new-...introductions/
Not knowing how old you are, or where you live, makes it a bit difficult to offer suggestions I think. Assuming you're still a minor & your therapist has permission to talk with your dad there may not be much you can do other than to simply present yourself back at the hospital & see what happens.

(I'm assuming you don't see a psychiatrist since you didn't mention one in your post. If you do, that would be the person to reach out to with regard to this.)
If you're perhaps a young adult at this point, then your therapist should not be talking with your dad without your permission. And if you gave it, at some point, perhaps you want to withdraw it & have a further, frank conversation with your therapist regarding what's going on with you & how you're feeling. But keep in mind I'm just talking in generalities here. A lot of this depends on your age & the laws where you live as well as other factors.
Where I live, therapists don't have any authority regarding whether or not a person goes to the hospital.

This would be a decision that would be made by a psychiatrist or other physician.

But perhaps things work differently where you live.

Perhaps other members, here on PC, will have some other suggestions they can offer.
There's a lot of support that can be available here on PC. The more you post, & reply to other members' posts, the more a part of the community you will become.

Plus there are the chat rooms where you'll be able to interact with other PC members in real time (once your first 5 posts have been reviewed & approved.) So please keep posting!