dude,
keep going. i'm in the same boat w/ ya.
you ask for advise and seeing as i've been where your at and not much farther ahead in the game... here it is.
get yourself some clipless peddles. first ride w/ em i fell over twice, first fall hurt alot, second one wasn't so bad. but after riding in em for about the first week, i'd never want to ride a bike w/out them again. (8 months now) it helps on the hills, it helps on your cadence, it helps on the legs, it helps on the breathing, it helps you push yourself farther every time you go out. (watch pushing yourself too hard or ya may end up yacking on someones hedges, i've done it once or twice.... sorry neighbor) but yeah if i were to give you one bit of advise that will help you push yourself harder but help you the most, get some clipless peddles and a good pair of shoes to match and your going to love that bike even more.
raise my water bottle to ya dude, keep it up. you'll get there.
kat