Very distressed about the awful condition of beloved goldfish--?

My first year of college I bought a black moor as a baby and gave it a one gallon tank to fit in my apartment. After freshman year, I joined a sorority and had to surrender my goldfish to my parents until I graduated and had a place of my own. Every time I came home, the fish seemed to have doubled in size, and I soon became concerned about its living situation, but I let it slide.

I graduated this June and returned home to find my goldfish in absolutely deplorable conditions. The now 7in long fish (tip to tail) about 2in wide was still living in the one gallon bowl. There was a filter in the bowl, but the water was still green with neglect. Horrified, I quickly set up an old ten gallon aquarium and transferred the fish into a better home.

Once in the tank, I was shocked at her appearance. There are white spots on her eyes and front fins, and one eye looks like it was damaged in some sort of trauma. Some scales were missing due to her struggle in transport, but quickly small patches of white fuzz grew over the wounds. Half of her beautiful tail seems to have fallen off in the other bowl, and parts of fins are torn on both tail and dorsal fins. Most concerning, however, is her tendency to float with her tail pointed up on the surface. She frequently swims quickly to the surface and appears to be gasping for air.

I realize that there are several parts to this, and I apologize for the long explanation, but I'm concerned about her health and how I should proceed with tank treatments. I'm fairly new to larger aquariums so any help would be greatly appreciated. My biggest concern is bringing this fish relief as fast as possible.