I feel almost overpowered half the time I play, while other I'll feel very underpowered. That's balance my friend. I don't mean to offend you, but you're probably just worse than you think you are. Don't let this stress you out as, most of us are/were! This is a game that will take some getting used to, so sit back and refine your playstyle and really learn the ins and outs of a titan. Also try some other classes because there is a chance that you might be better suited to a Warlock or Hunter. Try different weapons and different talent builds as well. This game is a blank template for you to make a character that is perfect for your playstyle, so take advantage of it! Best of luck to you sir! Hopefully soon you'll be able to find a playstyle and class that fits you like a glove and you'll kick that feeling of uselessness that I know comes along with getting wrecked in the Crucible.