It's SO hard to get back on track. It sometimes feels like a monumental effort. I think a lot of it has to do with forgiving yourself. You had a strong reaction to a very difficult situation. Now, you can have another strong reaction...one where YOU are in control. Tell yourself that you will have one good day. No matter what your inner voice tells you, find a way to do it for just one day. Then, at the end of that day, you'll feel so much better that you'll wanna do it again. Recommit like that every day and slowly but surely, you'll feel like yourself again.
I'm so glad you came here to post and for support. You're a really good friend who cares so much and you deserve to feel better.