I dunno, it sounds like a less than ideal situation for you.
I guess I could say that you're not alone. Middle age is very hard on men, hence all the mid-life crises you see.
I agree, customer service forces you to see the ugliness in humanity, but then you can take solace in the fact that you aren't that horrible.
Yes, men are the worst at talking about feelings. Even some of the best and brightest I know recoil at the mere thought of talking about feelings. And yet, if you open up a little, I've seen quite an interesting response at times. Guys I thought were totally shut down were receptive to my discussion and offered real insight and compassion. Don't assume too much.
I spent the last 2 years feeling what you're feeling now. There are two books that helped me:
Stumbling on happiness is a psychological approach to understanding the factors that lead to happiness or unhappiness, as the case may be. It's very academic, and can offer a rational approach to understanding this issue.
This is a great introduction to Buddhism, which offers a more understandable and realistic way out of suffering. It's not a religious discussion per se, but it is founded on Buddhist principles (which are more philosophical than anything). It's clear, concise, and logical, and the more you carry out the teachings, the more you can handle the hard parts of life. It won't make you super happy, but it will ease suffering. That's all you can ask for.
Good luck.