It's okay if your situation is too much/too dire to start HRT on right now. You would have at least a few months before any big physical changes start and it can be years before they're obvious. Even when they're obvious, the cis are kind of very easy to fool by boymoding. I think telling your friends will give you a lot of relief and support, and they might even be able to arrange you being able to go out en femme without your family knowing at all. It also sounds like you'll benefit quite a bit once you're out of your family's place and independent or with roommates you can trust - which can be a very large step, all that im saying is it just sounds like you get a lot of stress just from having to live in that home with (potentially or actually) unsupportive family.

Inpatient is only if you think it will be helpful. They might only focus on getting you into a safe headspace and to start outpatient therapy and get you started on, possibly, antidepressants etc. That may be all they do. They may not get you hooked into the gender clinic/healthcare stuff at all, it's too varied to say. If you were at my hospital, I know the psychs on call by name and history and I could tell you which days to come lol - but so much depends on their own practice and quirks and biases. It might be useful just so you're safe from harming yourself - but again, I can't guarantee what it would be like at your particular one. I wish I could... I don't think you should continue to self-harm. I know it can be quite relieving, but I doubt I have to tell you that that relief is only temporary. If you do self-harm, please be safe and take care of your wounds by keeping them clean and protected.

When I was at my worst OCD, I would get relief from anxiety by checking and rechecking (and rechecking etc) but that relief lasted maybe a couple minutes and I'd start doubting if I ever really checked or if something changed etc. And I would feel compelled to check again or I'd ruminate and obsess on whatever needed checking. What I had to do for long term relief was start on an SNRI and do a lot of therapy, and also stop checking no matter how much my brain screamed at me. Eventually, I was able to stop my SNRI after a lot of modifications to my life and about 18 months of regular therapy. I still every once in a while get the urge to check (like, did I put on my parking pass, did I turn the oven off, did I lock my door, did I close/open the windows, etc that kind of checking) but I'm able to deal with the anxiety of not.