Whippet, sounds like you are doing GREAT already!

As to downhills- it's way worse to be overconfident in downhills than it is to be cautious! Only go as fast as you feel in control of. I was SLOW and riding the brakes on all downhills, even little ones, until I had been riding a few months and now I feel I can go a bit faster but still be in good control. You don't want to get hurt because you feel like you "should" be going faster downhill. Ride SAFE and you'll be riding a lot more, instead of in bed nursing broken bones.