Rough idle and squeak noise

[RGA1215]

Hello everyone... I've had some issues with my 2001 Chevrolet Tahoe LT 5.3 today. It had been driving normal all day and was working perfect. But on my way home, I was stopped at a stoplight. When I was ready to take off, I hit the gas, just like normal. But what was not normal is my car started making this very loud squeaking noise. The car would not move while making the noise, my low traction light turned on and my speedometer was going all over the place. After a few seconds the squeaking noise went away and I was able to take off. I pulled into a parking lot, but I then noticed whenever my car is only in drive, and at a dead stop it idles rough and makes a weird noise. Just a few days ago I took it into the shop to have the transmission filter replaced and had an alignment done. I had the transmission filter replaced because it had not been done in a while and the car was having trouble coming out of overdrive. I do not have any check engine lights on. I was able to get the car to the shop kind of easily, with the exception of the rough idle. What could this be? Any help would be greatly appreciated! Thanks!

 

[RGA1215]

I should also mention that whenever I put it in park or neutral, my rpms raise back to normal, and it does not make the weird noise anymore.