Always Quitting Early

It rarely fails that I finish a "workout" thinking I couldn't possibly do any more. I don't push. I know it. Today was no exception. It didn't help that work was a bit hectic and I squeezed the workout in at the end of the day.

Treadmill
5 minute warm up, 1 minute stretch
2 min 6 mph
1 min 6.2
1 min 6.3
1 min 6.4
1 min 6.5
2 min 6
1 min 6.5
2 min 6
1 min 6.5
3 min 6
2 min 6.5
cool down

gravitron assisted dips 2 x 8 x 72lbs, pullups 1 x 6 x 72, 1 x 4 x 72 weak
bench press 1 x 10 x 35, 2 x 10 x 45 I think, not sure on the bar weight
cable chest flys 3 x 8 x 30lbs each side
tried to do incline bench but ran out of time and muscle