Headlights and interior/dash lights all of a sudden started blinking?

Driving home one night, my Chrysler’s headlights and interior/dash lights all of a sudden started blinking like crazy, then they went black. There was an odd sound that followed and then I lost power steering and acceleration. I was able to coast off the highway at the next exit and went as far as I could until the car came to a stop. I tried to turn the key to pull it out and couldn’t get it past the ACC and it’s been stuck there ever since. My husband was able to tow the car home but we are very tight on money so have not been able to get it to a mechanic. Prior to this incident, the car sometimes had difficulty accelerating. Even with the gas pedal pressed to the floor, it would not speed up. Only after a few times of taking my foot off the pedal and then slowly pressing down again would it kick into gear and finally pick up speed. Another issue was one of the belts (serpentine I believe?) Was squealing constantly. We did replace it, which helped briefly, but then it started screaming again. Could all of these issues be related — the car breaking down, the stuck key, the acceleration difficulties, and the screeching belt? My husband is somewhat mechanically inclined but I’d rather not spend money guessing if I can get some insight from you guys, especially if ultimately, it may not be worth it to fix. Any thoughts/suggestions would be greatly appreciated. Thank you so much for your time and for providing this service! :)