Hang in there and don't get discouraged!

Racing a hybrid bike is not easy, and depending on the quality of the bike it might actually be quite heroic to pull 13 mph on it! One of my bikes (Trek 7.1fx) is a really good hybrid and runs very smoothly, but I have another one which is heavy and clunky, made of much lesser quality parts, and it definitely won't go very fast unless it's down a hill!! (And even then, the wheels aren't so good so there's a speed limit too.)

Others will come up with other suggestions, but I think time in the saddle is at this point a lot more important than weight training. You might want to increase the duration of your rides, and try different training programs including intervals and hill reps (just like you're already doing). Doing drills of high-cadence spinning, you'll get better at moving your legs faster (it's normal to bounce on the seat for now but you have to keep practicing and you'll get better). Doing somewhat longer distances will help even if your race is short. It will also help you loose some weight, if such is your desire (especially if you adapt your nutrition to your training).

And keep coming to TE!

Cheers