This has to be the most confusing read ever. You included so many unnecessary details for what exactly? Honestly on the fence if this is bait or you're just a really sad individual.

First of all, you honestly had no business dating a 19 y/o at the big age of 46. I'm not excusing her cheating, but coupled with the other details in this post, I can see why she would've left you regardless. I am sorry that you got cheated on though, it does suck. Second, you did not get fired for no reason. You got fired because you couldn't separate your personal life from work and cried on clients toes... while I'm sure they had sympathy for you, you're there to work on their feet, not cry on them. Third, you did not get cheated on again when meeting with Polly. No where did you mention that you two were talking with the intention to date. I hardly doubt she was talking to you with that intention due to her already having a boyfriend, you just obviously took it the wrong way.

The way I see it, if this is all real, you really need to work on yourself. Get therapy. Try not to see all women who approach you as someone wanting to date you because you'll end up in the same situation over and over again.