An Emotional Break?

Well last night was bootcamp and it was a little bit different.  The one studio we use is now filled with state of the art equipment/machines (treadmill, elliptical, bike, weight machine of all different kinds, etc) so we did stations.  It was definitely a different experience to use all the different machine for some of the same exercises we've been doing and for some new ones.  Then we got on the floor, strategically placed between machines and did some core work and BUTT KILLERS and boy do they live up to their name!  YIKES!  Especially when you do them in a pyramid of reps/sets (meaning 1 set of 18 on each side, then one set of 17 on each side, then one set of 16 on each side, and so on....) YOWCH!  So as I'm doing pull ups on a machine intended for weighted squats, Tina comes over to help me and tells me that my legs should be straight and not with my knees bent.  So I put my feet out and try to pull up and it just isn't happening without Tina's assistance.  I tell her "I can't" (which I've discovered are two words you should never say to your trainer.) and walked my feet up.  The timer went off for everyone else and it was the end of the circuit so they were taking a water break.  She said "We're going to do it one more time" and reminded me of the straight legs.  Then I hear her say "And don't tell me you can't, you can."  I got in to position and with a little assistance from Tina I managed three more, but was physically and apparently mentally exhausted.  I'm not sure why but when I heard her say "Don't tell me you can't" and I started doing the pull ups again tears welled up in my eyes and it took all of my strength to not bawl like a little baby!  I was floored!  What was all of this emotion I was having all of a sudden?  Is this how the contestants on The Biggest Loser feel when Jillian starts grilling them about how in the world they got to 400 lbs?  Was I having an emotional break?  Was I just so tired and exhausted from all the rest of the stress of the day that it was just one more thing on my mind and happened to be the straw that broke the proverbial camel's back?  I don't know what it was, but I almost wish in that moment Jillian Michaels would have been there with me to pull whatever it was out of me.  Why was I crying?  I'll probably never know unless I fail on my own and by some chance make it ON to The Biggest Loser, or maybe a shrink somewhere down the line will be able to get through this confident, strong, front that I seem to have going?  Only time will tell I guess.