Poker's best and worst

I have continued to play tournaments while in Vegas, and I'm up over the last two days despite being down a lot since the onset of the trip. At several points, I've wondered whether I am an above average player or just another person feeding the coffers of Vegas veterans. I feel very confident that my math skills match up with the professionals, but I've learned a two things that have been my downfall. First, I don't have the courage to play solid no-limit poker. I am too frightened of losing all my money with anything but the best hand, and if you play from such a conservative position, you can be assured of sub-optimal returns. To counter this, I have only played limit cash games and tournaments, where your losses are capped for any particular set of hands. Second, when I placed second yesterday in a tournament, I got some of the worst news possible. The man who won told me I had an explicit tell whenever I look down and see two strong cards. A tell is something, a hand gesture or facial tick, which conveys something about your cards or intentions. Although I will try to control this going forward, this can be the knell for a poker bankroll. It appears that although I have the brains, I lack the composure to be a long-term winner. This is poker, for me at least, at its worst.