I have been cycling for about just over a year and the most I have done is 20miles which took me just over 2 hours. I haven't done that amount since and just averaged about 5miles each time but will get back to going out longer. I don't like cycling on roads so I am limited to where I can go as I got a little scare of a car passing me quite close which has affected my confidence but I will succeed and not let people like that get me down.
Things like that really can shake your confidence. You've just got to keep at it though.
My first major crash could have put me off cycling - and it did put me off cycling at speed for a while, but I improved my braking technique to ensure the thing that caused the crash didn't happen again.
Basically, I was cycling a route I often take, but I wanted to extend it further north - to have a long cycle of about 30 miles or so (total, 15 each way), I was doing about 20-25 but didn't realise there was a big hill just in-front of me. As I went down the hill I decided to let off some of the speed as I got faster, so did so with my
rear brake, saw a car on the other side and pressed harder on the
rear brake. It was at this time when I realised the rear wheel had become airbourne and I realised I was only partially on the road. I completely missed the other car, and somehow managed to stay on the bike for about 7 seconds before the inevitable crash down, plus a few rolls down the hill. Not pleasant, but nowhere near as bad as it could have been. I could've hit the car head on (would've ended up in hospital at least), or come off the bike straight away with no time to slow down (would've ended up in hospital).
Let me tell you, it's no fun to cycle back home with a large gash on your elbow, one just above your hip and one on your left hand (just where you grip the handlebars). A week after that I was commuting again, a week after that I got gloves to protect my hands should it happen again.
Keep at it, stick to the quiet roads, and you'll wonder what the fuss was about soon enough
Oh, just in case you haven't guessed it,
never rely on your rear brake to let off a lot of speed, this can often happen (as I've demonstrated quite a few times on my drive at home - safer being close to (at) home).