One golden rule to live by on a TT bike. Don't raise off the saddle to accelerate when your hands are on the aero-bars, only on the bull-horns. I did this the first 30 seconds I had my bike and I crashed too. My TT bike is not as stable as my old road bike was by far. But I have to say I can't see riding anything else. Just give it time and make sure your not too stretched out.