Hi LovesFrance,
Good for you that you're out there doing something that you love.
I'm in that 40 yr old club, have lost some wieght, gotten alot healthier and enthused about cycling, too.
I can only share what my experience has taught and this is just my second year in the saddle
- so here goes.
First, you might try using a helmet or handlebar mounted mirror so you can check for traffic behind you. My fear of traffic has decreased the more I get out there. Still, I don't like trucks pulling trailers of any kind. Gives me the heeby jeebies. Always ride defensively - look around all the time, stand up in the pedals to let a car pulling from a side street know you are coming - I can't tell you how many times I think this has really saved me. Still, expect that some drivers will try to jet out in front of you just to beat you. Truth, the more you ride out there you WILL gain a bbetter level of confidence. Just takes time.
Downhilling - this year I'm tucking on familiar hills. It's a rush!!!
If conditions are sandy (the after snow stuff left over from winter), unfamiliar or wet, I sit up, coast and brake conservatively.
Really, do what you need to in order to feel most in control. Again, the more you ride, the more confident you'll be. Guarantee.
I hope you'll get more responses that will encourage you.
Dum vivimus, vivamus!
(While we live, let us LIVE!)