I would reccomend playing slow tournaments at the DHLC (dan heisman learning centre) http://www.chess.com/groups/home/dan-heisman-learning-center
they re-create OTB tournaments really well, when I first started playing at the DHLC I was very nervous every game and kept offering early draws ect and also found it hard to concentrate for any length of time but now after around six months playing at the DHLC I am confident and enjoy every game and now i feel that a 2hr game is quite short and prefer 3hr+ games and also I have almost zero nerves now as i am just playing for fun and i do not have to feed my family ect on winnings so when i do go to OTB tournaments i enjoy them and have very little nerves just like when i play for the DHLC :-)
I don't know is chess is good for me. I can play almost no OTB, because where I live there are very few OTB torunament, and most are only blitz. But even if I can play, I am very nervous when playing OTB. If you tell me that I'm going to play an OTB game tomorrow, I would be very nervous. When I sit, I can't think because I am very nervous, and I make stupid blunders, like hanging pieces or overlook a mate in 1. Plus I can't resist for so long. After an hour I feel already very tired. In my only OTB tournament I lost to weak players hanging pieces, missing simple tactics, ecc... I was winning against a 1900, then hang 3 pieces and lost the game. Maybe chess is not for me?