Originally Posted by HiYoSilver

First of all, congradulations on making the first big step. The first 400 miles are the hardest.

Second, you need a gearing change. It'll take about 1,500 miles before you really have developed the engine so you don't have to worry, Until then, use gears. You're lowest is only 23.9 gear inches. [Roughly the number of inches you move in one revolution of the wheel. Don't worry about the term, it's just a unit of comparison.] You want to be have a low gear around 20 GI. Best recommendation with curerent bike: Have shop change out lowest gear to 22 tooth chain ring. It would be best if you could swap out the cassette and get one that goes down to 34 teeth instead of 32 like you have now. Single swap you'll drop to 18 GI. Double swap you'll drop to about 17 GI. That's like 3 extra low gears.

Don't focus too much on losing weight, you need to convert weight to working muscles.

Fourly, you might consider getting new bike now, as often you can finance at very attractive rates. But if you do, watch gearing. The "standard gearing" is setup for lighter riders and doesn't adequately address the needs of the heavier rider. You won't save much weight on new bike, but would gain: more gears for easier adjustment of gears to hills,
The bike will give you a better ride.

Finally, don't even try to keep 80 cadence on hills. Shoot for something more efficient in the 70 range. Below 70 and it can get too hard on the knees. Above 80 you're burning too much energy trying to spin. I usually shoot for 75 as it's an easy number to remember.

Good luck, let us know. Oh, also don't forget to get a good nights sleep. You'll need it for the power you need to use.