Hey Emma!
I went through derealization/depersonalization aswell. Worst thing I've been through, especially not knowing anything about it. I actually thought I was going out of my mind.
To put your mind at ease - It's not going to harm you in anyway, you won't lose control or go crazy and it won't stop you from doing anything. It's near zero chance that it's permanent.
To get rid of this, you need to have patience. I know it's hard, but that's the key. Ideally, you also want to learn to control you anxiety/panic/depression. I found a combination of supplements, exercise, meditation and a healthy diet which helped me alot. It can be anything, but learn to deal with your anxiety. Because it's the anxiety that's causing the DR/DP, not vice versa.
Once you've dealt with your anxiety, learn to not fear it. Don't fear that feeling, because it's the fear that's causing the feeling and making it stay. Once I knew it couldn't harm me - I started enjoy it instead. And guess what? It disappeard. Life is funny huh.
Just live your life normally, as if it's not there. It's hard, but fake it til' you make it. Because feeding it and always focusing on it; is what's making it stay!
Wish you the best!
Elias aka Proffesor deReal