Tapping and random cylinder misfire at idle and other

I have a 1996 Pontiac Bonneville SE automatic with 147,000 miles. I was recently driving and did not notice my car was beginning to overheat due to a leak in my lower radiator hose and soon found myself on the side of the road. After cooling down and duct taping for a quick fix until I could get to a part store, my car displayed the check engine light and gave code for a random cylinder misfire as well as a tapping sound while idling. Car also seems to be losing power when climbing hills and when accelerator is pushed nothing happens at times and I must release and push again and car will rev up and begin to gain momentum. Idle is sometimes rough when car is warm and hessitates when taking off from a stop and has died on a few occassions if brake and gas are not applied in order to bring rpm up take go when rough idle occurs. What are your thoughts?
More recently, I was struck by a car that thought stop signs did not apply to her but only my rear passenger wheel was hit causing the top to be knocked in \ and very noticable, is this bent and not repairable or can I purchase the rear wheel assembly and whats the proper name. Thanks