It be nice to read of your training process and current physical condition…something measurable…type of group ride, skills of the group, the typical course, altitude gains along with your average speed, watts, sustained pace/cadence…something.

I’m guessing you are new to this…and that’s okay…as with more miles and seasoning you’ll understand the specious concept that the bike makes the rider...and why I'm not answering your question directly as I'm confident your problem is not with the bike.

Immediate gains over that of plunking down money for a sworks [or whatever higher end] would be your physical condition [strength to weight, training program, coach if necessary] and that of a professional bike fitting [see Serotta, the Fit Kit, Retul, Bike Fit Systems, Specialized’s 3D Advanced BG Road Fit] along with focus on your pre & post ride as well as "on-saddle" nutrition.

Start smaller. No need to get spanked each ride. Get into a no-drop group ride and work up your pacing and speed over longer hauls as you build strength. From there learn techniques of speed and maintaining pace with advanced group rides.

New bikes, components, wheels will come as the margins between first and second place interest you…otherwise, don’t spend more money on a higher end bike until you can ride your current bike comfortably in the first quarter of a good group. Ride well.