02 Sebring BIG problems? Don't know if its transmission.

[iluvdiznee]

I was driving home today and started hearing a tapping or rattling sound from the drivers side, possibly under the hood. I slowed down so I could hear better. When I slowed down the car jerked forward like someone had bumped my in the rear bumper. I pulled off the road and looked at my dash. No warning lights were on, no smoke, and sitting idle, no sounds. I put the car in park and turned off the engine. I sat for half a minute and decided to see if it would start. It did with no problem. Everything "appeared" normal except when I put it in Drive. The car jerked forward like I was rapidly tapping my brakes and letting off. I immediately put it back in park and turned it off and called my husband.
Someone pulled the car home and said it had a nasty sound coming from the underside while they were pulling it. They said it went into neutral just fine though.
My husband decided to check my oil when we got the car home and he said that it was almost empty, yet my lights have never come on, I have never heard any odd sounds, and I had my oil changed a few months ago.
He checked the transmission fluid and it looked OK except it smelt of burnt rubber. If anyone knows MAYBE what this may be I would appreciate some guidance. I just need to know what I may be looking at.
Thank you!
***edited*** Weird combination of issues all at once. Oil loss, transmission fluid loss (not a lot), and the sound I heard IS there. It is in the "axle" area. It is audible going straight, not necessarily turning. Doesn't appear to be transmission, but everything combined doesn't make sense!