Q: 2007 Chevy suburban stabilitrak off, traction control off, reduced power, hard shifts,

A couple weeks ago, stabilitrak, traction control warning lights came on and power was immediately resuced, hit a bump, lights went away and power regained. This week, issues occurred again, this time the vehicle wouldn't shift into drive or reverse from park. Restarted vehicle and can now move but when it is put in gear it shifts hard. I can barely make it to my mailbox. I've looked into the problem and being told a lot of different solutions, none of which are cheap and it is frustrating because "everyone has the fix". Some of the solutions ive been told are coil springs, throttle body, wiring harness, brake pedal sensor. I read the codes and it says the #6 cylinder is mis firing, and u0121 lost communications with ABS. I have checked the ABS fuses they are intact, air filter is in great condition. I have low tire pressure in one tire and a bad emissions sensor. Thank you in advance for your time in regards to this matter.

My car has 180000 miles.
My car has an automatic transmission.