What field were you in? Cat 5 only, this would be discouraging. But if you were in a 3/4/5 field, or Masters - you are up against much faster racers.
My only addition to the comments above is - if you are really serious and have a few extra dollars to throw around - invest in a power meter. You can get a second hand powertap setup for 300-400$. This will tell you EXACTLY how much power you are putting out in a given effort. You can then base your training around that number, giving a better focus.