Do you have a power meter? If so, what is your Power @ FTP? What is your weight?

If you noticed that you got passed on the hills and weren't getting passed on the flats, or passing people back, power divided by weight is your number one problem. Either you + your bike are heavy, or you don't have enough power on the bike. Or a combination of the two. You can work on both power and weight, or just one (while not making the other worse), and the ratio will improve and you will go uphill faster. But if you're losing tons of time on hills and not on the flats, weight is probably your #1 problem- there is probably room for significant gains in race performance.

What type of workouts you should do will depend on what type of racing you want to do next. More half iron? Or switch to Olympic or Sprint?