You didn't say what your goals are, but you did say you wanted to focus on cycling. My experience with triathletes is similar to RacerEx's, one speed, fast, but they have trouble with the surges. Bike racing is all about surges and surviving them. You're not going to improve this if you're riding at an even pace. If the strong guys go on a hill, don't go flat out until you blow up, go at 90% and try and keep that going as long as you can. On the flats, take your turn at the front, don't just sit in. This will build your FTP and hopefully gain enough respect from the group so that they won't mind waiting at the summit.
Good luck and have fun. And don't worry about crawling home. Everyone has at one time or another.