Afraid of stopping and down hills

[dlolide]

Hello everyone,
I'm a newbie to road riding and this site. I have ridden a few times with my husband and have done a couple of 10 mile rides around the lake, but I have a big problem. I have a fear of taking off, coming to a stop and going downhills. When I first get on the bike and take off, I am all over the place. I can't seem to balance myself right away. When I see that I must come to a stop, I panic. I clip out of one side of my pedal but I lean to the other side to stand (with the foot that is clipped in, I know dumb) and don't know get of my seat. In other words I don't know how to stop without tipping over. Also, I fear downhills, I start going too fast, so I hit the brakes and feel like I will slide out into the pavement, which I believe is not proper due to other cyclist going down hill at high speeds. Does anyone have advice on how to get over these fears? Thank you.