I was the same age when I bought my first real road bike. Mostly you need to ride as much as possible, except that you probably can't much right now because there's snow, right?

Yes, Friel's The Cyclist's Training Bible.

I'd park the swimming and running for now. Ride your trainer and work out at the gym. At the gym, Friel has you start doing circuits with 3 sets of 30 on about 7 different exercises. I recommend that very highly. You do that 2-3 times per week for a few months and it will make a major difference. Ignore the bodybuilders.

The StepMill, other Stairmaster machines, and elliptical trainers are also good. Spin classes are great if your gym has them. Running stairs is also good. Stadiums or tall buildings.

You're very tall. Be sure your bike fits you properly. Manufactured bikes weren't developed with you in mind. Even 180 cranks are too short for you. You may eventually want a custom frame.