The only way to get to the place of letting go of what society is pressuring you to want is to go through the pain of realizing that what everyone and everything external to you wants for you no longer feels good, and that you no longer have interest in pursuing it. But, setting that aside, not that you really can (or assuming you are on your real path that is most authentic to who you really are), the real way to get to the place of power that is living in the pursuing/not-pursuing tension is to ultimately be okay with never having that which you are convinced you most want.

The single biggest mistake most people make in trying to get happy is that they do more things that make them happy. In fact, that is only half the battle. It's the easy part! What needs to happen before that is far more difficult.

It does you no good to be all macho and hardcore, pretending like you’re tough and nothing bothers you, because it’s a lie. And the more controlling and jealous you are, the more you reveal just how terrified you are. For jealousy equals fear; always, always, always.

The very thing the man was most trying to avoid - his girlfriend cheating - by having his girlfriend spend less time around other men and her friends is the very thing that he basically creates by cutting her off from her sources of joy. By reducing her positive sources of happiness he drives his girlfriend to find maladaptive, non-constructive sources of happiness. 

This snippet from Joseph Campbell comes from "A Joseph Campbell Companion: Reflections on the Art of Living"

...of course, the wonder of it all and the endless tedium of those who drone on and on about ‘untreated depression’, “I’ll be there for you if you’re considering suicide”, and all the other overwrought blather.

Suicide.

I mean, we’ve all thought about it, at one time or another...

It is one of life’s ugliest, yet most beautiful paradoxes: creation and destruction are forever inextricably dancing; pain and joy live in the same breath; blessings and curses can never be extricated from their mad embrace. We, it seems, need only have the eyes to see, and the courage to look into the eye of the beast that afflicts us at any given moment or period of life.

Ask yourself one basic question. It’s not the cure-all question, but it gets us in the ballpark. What do you do when you’re at Starbucks, after you’ve ordered, and waiting for your drink? Or, for church-going folk, perhaps while you’re standing in line to exit the sanctuary at the end of service? Or, when you’re standing on the platform waiting for the subway? Or any line anywhere, or anytime people are around? Why?

The real success is in sticking your heart out there and loving and choosing to NOT live in fear. For, again, all of life, every decision boils down to that fundamental choice: fear versus trust. It's not even fear versus love, really. We all feel love and want to express it; it's our natural state. But what keeps us hamstrung, what keeps us from expressing that love is that we fear getting hurt. We fear that we won't be okay, that the pain will be too great, and that we just explode or die from the pain.

These aren't just stories; this was a man's life, a man who was sitting across a table from me drinking his Starbucks, a man who at one point wiped his lips after taking a sip and part of his napkin stuck to his lip when he pulled his hand away, as it might on any of us. A man like any one of us, yet a man who had been to hell and lived it for six years....and a lifetime since.