changed out the thermostat and its still over heating and you can smell antifreeze out of the exhaust.....is this a headgasket? or maybe something simpler. its a 99 2.5

 

Check for oil in the coolant overfill/filler neck and coolant in the oil at the oil dip stick.
If those are fine, it may be time to flush out the coolant and the radiator. Another thing to do is to make sure the front of the radiator isn't filled with leaves, bugs, and any other type of gunk. Make sure the fins aren't all bent. Also run the car warm until the fans come on to make sure the fans come on at all. If they do come on, make sure the fan switch works, better yet, change it out with a new one since it's probably the original.
Do the other stuff first before you focus on the head though.