No codes yet definite issue, the vehicle is having a hard time getting up to speed in order for the transmission to shift from gear to gear?

My vehicle listed above still runs but it does not want to. When driving there is no problem shifting into gears, but it clearly is having a hard time getting up to speed in order to shift from gear to gear. There are no codes on the dash. Also, there is some type of lubricant leaking from somewhere as it is dripping down to the exhaust causing smoke once the vehicle has been on for a few minutes. The car is not overheating. Checked oil for engine and transmission fluid. I expected one of them to be low as there is clearly fluid coming from somewhere. The dipsticks read appropriately. I have done a test for the head gasket by seeing if there is any air coming up and out of radiator with the cap off and car running for 5 minutes, there was none.