It's always hard when you have to admit to yourself that you're not happy. I don't see that so much as giving up as really just coming to terms with what is your reality. The most difficult thing is knowing that the environment that you're in isn't going to present you with what you're looking for--and maybe being in a place where that isn't present actually enlightens you to what that thing or those things are.
It's not that you aren't willing to do what it takes to find it--it's just that regardless of the leads you have followed and the efforts you have made, nothing has really materialized. And, I think the toughest thing is not really being able to talk about it either because no one is going to have a clue what you are trying to express, you just don't have that kind of relationship with anyone, or you just don't know what to say in the first place--or all of those, or maybe none of them.
I wish I had something enlightening to say. Unfortunately, I don't.