EL XR6 TOWING

Hi guys, Im a NooB! So Yesterday I towed a single axel trailer (Full)- Household furniture for 4hours which should have only taken 2 hours on my EL XR6
She chewed through the gas, crawled up the ever so small hills (Felt like it was loosing power) when it was in 'ECO' while topping the nerly RED of the 'Normal" Temp Gage (Uphill only) and temp would drop right back down when we levelout, she got so hot around the footwell area and heated up the cd i was playing in my headdy, so switched the ECO off and she jumps up to 3-4000rpm at 60km???WTF she takes forever to change into the third gear while ringing my ears out from the horific big bore! I had the pedal to the metal and she would not go past 90km on a straight only if we were to go down a hill which was also weird as the car didnt take gravity and roll down the hill it sorta Drove down it (If u know what i mean?And everytime i slowly put pressure on the brakes coming down the hills the front of the car and steering wheel would shake the hell out of us any suggestions guys/gals? Are these things common in EL XR6s?
I have recently taken a keen interest in DIY approach so would like to do few repairs myself if need be.
She chewed through the gas, crawled up the ever so small hills (Felt like it was loosing power) when it was in 'ECO' while topping the nerly RED of the 'Normal" Temp Gage (Uphill only) and temp would drop right back down when we levelout, she got so hot around the footwell area and heated up the cd i was playing in my headdy, so switched the ECO off and she jumps up to 3-4000rpm at 60km???WTF she takes forever to change into the third gear while ringing my ears out from the horific big bore! I had the pedal to the metal and she would not go past 90km on a straight only if we were to go down a hill which was also weird as the car didnt take gravity and roll down the hill it sorta Drove down it (If u know what i mean?And everytime i slowly put pressure on the brakes coming down the hills the front of the car and steering wheel would shake the hell out of us any suggestions guys/gals? Are these things common in EL XR6s?
I have recently taken a keen interest in DIY approach so would like to do few repairs myself if need be.