towing with an automatic

So I just got back from my first long trip towing with my new set-up. I am towing a 26' travel trailer with my 2008 suburban. My set-up tracked good with no sway, and was stable in all conditions, we had wind from every direction, passed people, were passed two lanes, a good test, and everything went great.

The only problem that I really found was I had a heck of a time keeping the suburban out of second gear. I was driving in third in tow/haul, between 60 and 65. It seems I couldn't give it much throttle and back to second it went, running up to 4500rpm. This drove me crazy, I wasn't in a race to get up to speed, I just wanted to slowly accelerate. Once it got to the speed I wanted, it held it well, but I couldn't see a need to down shift so quickly. I guess I will get used to it, but changing from a manual where I controlled everything to an automatic was quite frustrating. I seemed to learn to manage it better the more I drove it, but I had to really be careful to not push the pedal more than maybe 1/8" at a time or second gear here we come!

Is there any way to better deal with this? Will a programmer take care of this and allow me to give it more gas and just stay in gear?