Ok so today at the gas station, I was on a hill trying to back up when tires spun something broke I’m sure because there was a bang and sounded as if something fell out. Shifts into all gears perfectly fine but when put into reverse it clunks and bangs and stalls. Sometimes, the shifter gets stuck in reverse and I have to try to go a bit to get it unstuck. What could I have broken and how hard do you think it’s to fix?