Are you riding 52-42-30 chainring and a smallest cassette cog size of 12 teeth? I strongly wonder if your mates are riding at least 53-39 and have an 11 tooth on their cassettes. This would certainly provide the potential for higher speeds but then other factors would have to be considered as well, e.g:
I'M NOT SURE ABOUT THE ABOVE.
Have these guys been riding longer and / or training any harder than you? ONE HAS. THE OTHER, NOT QUITE AS LONG AS ME.
Is your bike set-up giving you any disadvantage in terms of aerodynamics? I THINK IT IS GIVING ME A DISADVANTAGE, AS I THINK THE FRAME IS TOO SMALL. I FEEL SQUISHED TO THE FRONT OF MY BIKE.
Is your bike set-up giving you any disadvantage in terms of comfort and prematurely fatiguing you? SAME AS ABOVE
Do you have comparable strength/weight ratios? I REALLY DO. IF ANYTHING, I AM PHYSICALLY STRONGER THAN BOTH.
BUT HOPEFULLY IT WILL ALL CHANGE, AS I AM PURCHASING A NEW BIKE THIS WEEKEND OR COMING WEEK. I CAN'T WAIT.
etc etc etc...there are a LOT more factors that would affect your relative performances than the just the type or value of road bike that you ride, often including the oft-unfortunate one that we are certainly not all created equal, particularly in terms of our physical abilities! That is not to say, of course, that this is the governing factor here, or that there is no room for improvement or success!
Good luck with it all - keep persevering and don't lose faith!