Horrible setbacks

I've been so incredibly happy lately, and then two days ago something horrible happened. I can't say what it was, I just want to forget it, never remember. It felt like a nightmare. I was in such disbelief that I didn't understand how it wasn't one, how it could possibly be real. All my self-confidence that I've accumulated was demolished in one blow. I hated myself. I was taking my meds, but I was SO depressed. It's horrible, knowing you're on your own with depression, knowing no medication can fix things.
For two days I've felt so horrible that I must have been in Hell. I felt... major depression, suicidal, guilty, ashamed, self-hating. I thought I was a horrible, disgusting person. I wanted to self injure very badly, but somehow I didn't. I did feel so dirty though that I took a fourty-five minute shower and scrubbed my whole entire body until it was pink and raw. I put on all clean clothes, brushed my teeth, and held a bar of soap in my mouth for two minutes and washed it out with the bitter stuff.
I didn't tell anyone for a long while. Tonight at dinner, as I was emotionally binging on Chinese food, and felt, as I have felt constantly for two days, on the verge of tears. Finally I just cracked and started sobbing and my parents finally got me to tell them what happened, and I'm not all alone anymore, they're helping me. It was horrible telling them though. Maybe not worth it.
It will be a long time before I truly recover from this. I think I'll just have to work on every day trying to love myself again, trying to put this behind me, treat it like the nightmare it is. It'll take a long time. It'll be slow progress. But I have to keep going. I can't get stuck in this rut.