1996 Dodge Intrepid Loud noise upon start-up and during dri

ITS ALSO THE 3.3 not the 3.5.

I recently found myself in a bad position on y way home from work when my car started making a loud high pitched noise coming from under the hood. I had no idea what it was. So I ignored it and drove around for a bit to see if it would stop. And it did, for about 2 minutes until I pulled onto the main road and accelerated for about 30 seconds. It then started making the noise again. This time a little lower pitched. I realized that it was a bad idea to be driving it if it could cause a major problem and went to pull over when my just STOPPED ACCELERATING, it then went back into acceleration after turning to go into a parking lot. I turned the car off, popped the hood and put a little transmission fluid in thinking it was low. About a 1/4 of a quart. I started the car and let it run for a bit then decided to see if it would behave and tried to drive it around a parking lot. Well it didn't, it just completely stopped moving. No matter what I did(reverse, drive, etc.) The gears apparently never caught. I ended up pushing my car into a parking space and had to get a ride home.

I went back the next day so that it didn't get towed to see if it would move. And it did. I drove it for about 1 city block down the road before I had to pull off and get it towed back to my house because it was making the noise and stopped driving again.

What could cause the loud high-pitched noise and what could at the same time cause my vehicle to stop working.

BTW. I was told to try to replace the transmission filter and flush and replace the fluid, and the oil to be safe. I haven't done so but I do have the parts for it.

PLEASE HELP.