Start to the second week...hard day

This was not how I wanted to start the second week!  I was drained by a long and bad day at work. I made myself show up for class about 20 min early because I knew if I sat down for just one min at my house I wouldn't go to workout. I think I had probably my worst run yet in the warm up (I was out of breath and my knee hurt). I stretched and then started the workout (pushups, squats, and thrust kettle bell swings--3 reps of 10 each). Half way through the second rep of kettle bell swings I found myself wanting to cheat. For a second I thought about stopping but then I realized what I would be doing. I would be wasting the money I spent on this training and ultimately cheating myself out of what I want and NEED. I would be giving up on myself. Giving up on the idea that my life could be longer and better!  And, even though it hurt like hell, I finished out my reps. I thought that I had overcome this mental weakness of wanting to quit until we got to the next exercise. We did some weight lifting and then did sit ups. The sit ups were very challenging and eye opening to me. We had to lay on the ground with our legs in a butterfly stretch position, arms stretched out over our heads, and sit up to touch our toes. Needless to say I wasn't great at this and there were times when I laid there thinking I didn't have to do all of them!  I did skip out on a few of them. I was frustrated that my body wouldn't do what I wanted and needed it to do. I was frustrated that I had let my body get in the shape that it is in at this point. It was a frustrating day for me, but I think I learned that I always have to just keep looking forward to what I want for my future and not dwell on what I haven't done for my body in the past.