Fix or sell?

[why?]

Fix it. Go to a good body shop that will warranty their work for life, and let them replace the entire thing.

I sideswiped a stop sign on a dark and stormy day, and the quarter panel like yours was messed up badly. I took it to my insurance, found the best body shop in the area. The fixed it up perfectly, gave me 3 different lifetime warranties, 1 from the shop for the work, 1 from the paint company for the paint, and 1 from the insurance company for everything, and it is good as new.

Even if the accident is your fault, your insurance is there to pay for it. The premiums won't rise that much. Plus a fixed car will get much better gas mileage.