This is not a show about energy and vitality. The main character has been completely broken, he had been captured and tortured (before the series started). He's completely numb. Also, he is not a very nice guy nor is he likable, he's doing actual spy things and doing them to win. He's ruthless.
It's a very dark series but I'm not going to say anything about why I loved it, outside of the fact I was completely invested in a half dozen characters.
I'll add that the show didn't sink it's hooks into me until the third or fourth episode (I was playing Civ at first) but when it did, I turned off the computer and it had my full attention. This actually left me a bit lost because the show is so damned complicated.
Shame you didn't like it, I think you're going to miss something special here, but it definitely is extremely dark... Although at times it's light and hilarious. It's like Wes Anderson killing a brutal hangover with Xanax.
I've been watching it again on my phone as I commute and I love it.