1995 Saturn SL1 Problem with transmission/electrical

Two days ago my son told me the battery light was staying on.
Last night he told me that there was no power stepping on the gas from a stop (and some bucking?)

I took it for a ride this morning. Started out in reverse to back up. Took off and I thought it was running really good. Stop sign and a let turn/ no problems. Red light and a left turn/ no problems.
Drove a straight mile and it was running beautifully. I was wondering what the heck he was talking about.
Aprroaching a red light I was stopping as I turned on my right signal. Immediately the radio went off and then back on for a second and then back off and stayed off. As I was wondering what just happened, the light turned green and I stepped on the gas and I had no power. It very slowly got up to speed. The engine sounded fine. I turned around and still no power. As I got up to speed I kicked it down a bit and NO passing gear.
I pulled over and started from a dead stop and payed close attention. I have no power because it seems to be starting from second gear. Listening closely and I don't hear or feel it shifting at all. Just staying in second gear.

I also noticed after this that it now bangs hard when shifting into reverse.

The radio hasn't come back on.

This radio was just installed a few weeks ago by the previous owner. (My nephew's kid)