an awkward situation that makes me think quite a lot

I have a question though, about an episode happened yesterday at the gym, concerning impulse control.
I went to the gym yesterday: just a few guys and me, and then...a woman with her daughter who's around 10-11 years old I found attractive (not particularly, only her body in general seemed interesting to me).
And it's the second gym awkward situation, with another little girl (already happened one with another girl one week ago or something).
I was sitting at the pectoral machine and was about to start the exercise again, when I saw her not very far from where I was I suddenly got very anxious, then began the exercise to end it in a kinda aggressive way and breathing out heavily, as if I were angry.
Many times I'd take glances at the girl and then just look away and pretend nothing happened. Other times I'd stare at her when she could not see and nobody was looking (there was almost no one in the gym, so it was not easy to be seen).
What's weird about it is that I don't understand much what really happened...after all, what was all that anger about? Maybe frustration? Why was I being so obvious in the first place?!
I'm usually aware of my feelings and actions, what went wrong yesterday?
Makes me think I'm having a hard time reacting to my own feelings...
control of the situation just slipping?

I can't really understand myself at times!

When it comes to Paraphilias it can be extremely distressing, as you no doubt have noticed. One of my Paraphilias is Zoophilia and I almost can't control myself if I'm in a situation when there is a larger dog and I'm by myself, even for a split second.

The anger you felt, I would agree, is likely a subconscious frustration that you can't act on your lusts. Paraphilia in both of our situations is a detriment to our otherwise calm and rational persona's. Thus why we would be considered as a Paraphiliac rather than simply having a strong fetish, due to its distressing nature to us (or possibly others).

I'd say the best thing you could try to do is simply force yourself to be aware that you are in stat anxious state of mind when an episode like that occurs, in an attempt to calm yourself from your desires.

Or it could also be frustration coming from the fact that I had certain sexual thoughts once again, like a "flash" which suddenly appears in my mind out of nowhere.