The ups and downs!

I always post like soooooooo many threads about questions, concerns, ect. Well, I thought about documenting my lesssons/shows and everything else. Also ask some questions for you to help me with
When horses run, think of it as a game of tag with the wind~ Tre Tuberville
5/29/11-Cantering Lesson
Today, I had a lesson at 3:00. I arrived at the barn with time to spare. Secret was a sweety. She was in a different pasture and was with only one of her little friends, Archie. She stood still as I approached and I clipped the lead rope on and she led away easily. She wouldn't race ahead. She seemed relaxed but yet alert. I was very happy and proud. I cross-tied her and my trainer went to get her horse, Tina. Well, the other horses decided "O lets just run away". So Sweepee, Whiskey and Sam were on the loose. We locked them in Archie's field and they were running Archie over. I put Secret on another set of cross-ties so they could put Sam and Sweepee away. I led her just with a halter and she was so good. She was a little frightened by calmed down. Finally, I put the saddle on and I am sure she is getting fitter as she looks less fat and more lean not like underweight. Just, I could go up a few more holes on the girth. She was good with the bridle and took the bit without throwing her head up. Yet another proud mommy moment. . Anyway, finally I got to ride. It was so hot like 85 hot! Erk! So I worked on extended trot on the long side. But since I have been cantering Secret whenever I kick her coming out of a corner, going down the long side, she canters. So, I just made her canter, since she decided ohhh I wanna canter. I made her canter almost the whole ring. She has a bumpy canter and it hurts my back SOOOOOO much. Like I got her to canter the whole arena almost. I was so happy but it hurt my back so much. It shouldn't be like that as I am not old or have had any promblems with my back. It just hurts when I canter since all that strain. It really upsets me cause like I think I am riding her in round-up, cantering. It hurts so much, I don't think I can? I have to email my instructor about that. Anyway. It was a good lesson and I trotted her up and down a hill. I had fun and we hosed her. So that is about it.