Learning To Drive: Nervous Wreck

Hi all. I'm 16 years old in upstate NY and i just got my permit about 2 months ago and i've only got an estimated 4 hours of driving time so far. Ive always wanted to drive, I couldn't wait to get my permit, and I can't wait to get my license. Problem is I'm a nervous wreck while driving, and because im so nervous i sometimes can't concentrate.

About a week ago I was driving and i came to a 4 way intersection and I stopped. Once the light turned green I was about to go, and there was another car comming in the opposite direction of me, going straight. I'm not a good estimate at distance or speed but I'd say probobly 55-65 yards away going about 35-40 mph? I considered this fine and made my turn, by the time I had completed the turn, they were just getting to the intersection, they didnt even slow down to go through. My mother freaked out and said I shouldn't have gone there and I should have waited. She was screaming for a few minutes after that then she calmed down and appologised. Ever since then ive just been soo nervous whenever I drive, and maybe even anxious. My eyes tend to unfocus sometimes and I have to force myself to concentrate even harder on the road around me.(I don't wear glbuttes and I have perfect vision). Was the other driver too close and should I have waited?(Like I said im not good at judging distance and speed)

Today I went driving also(just got home) and did pretty well, until the we got close to home. I was on the road and about to turn onto my road(20-30 yards away?) and i was paying attentino to the road ahead, and a truck that was turning onto the street I was on and I didn't realize that the car right ahed of me was slowing down to make a turn and almost hit it, but I did slow down in time.

Anyone have any tips for me to be more confident while driving?

Thanks, Justin