Hello everyone, first time posting here!

I have problem with my bike (~20" MTB) - I hadn't ridden it in around 2 years, stopped after I got injured (broken foot and arm), so I decided to start cycling at from home to college. I have restored the bike about a week ago, which involved me oiling all the moving parts, checking brake cables (mediocre V-brakes), checking tyre pressure etc - all the usual stuff really. I did not thoroughly check the rear derailleurs, although they seemed to function properly (skipped a few gears, but I don't mind that ).

I was on my way from college a couple days ago, and just before I pulled into the sidewalk I switched gears from 4th to 1st; this made the chain slip onto the area between the wheel hub and spokes. I was going pretty fast, so I didn't have much time to react, and unfortunately the back wheel locked up. I knew it was going to be pretty bad. I got off and checked the rear derailleurs - I know they were pretty fudged up so I walked the rest of the way home.

I have finally had the time to check the bike for damage etc, and it seems that the RD is in a position which doesn't look good (I apologise for my lack of mechanical knowledge ).... looked like it was in the fetal position
I can't for the life of me figure out whether the derailleur hanger is bent, or whether the RD itself needs replacing. I have some photos below, and I will upload a video soon.

Thanks in advance!