Don't get too cocky now...

So I've been learning to drive, so far I have had three lessons for a total of 4.5 hours. And I thought it was going pretty well. My instructor thought I was doing well, I've mastered quiet roundabouts (rotaries?) with no extra traffic on them, turning, braking smoothly and I'm better at using my gears. Not to mention that I haven't killed anyone....yet. I've done a little reversing, hill start/stops and felt my general fear of "driving" had waned and I felt in control and capable of doing it, sure I might make mistakes but I'm learning and the majority of the time I'm fine.
Well yesterday it all went to pot.
I'd been driving happily at 30/40mph in my last lesson, and I guess my instructor just thought I was finding it all too easy...we started the day's lesson on a hill (please remember my actual driving time at this point is 1.5 hours) and he has me drive to a nearby village through the countryside at 60mph.
O............M...................G
Firstly these roads have no markings so it feels like I was either driving too far out or trying to drive in a ditch...other traffic out here does what it wants NOT what it's supposed to....it's so freaking fast I can't think straight...I got behind a line of traffic and had to practise driving behind people at 60mph and it was terrifying. Some roads look as if they go straight but actually curve sharply to the left.
I encountered my first ever traffic lights on this road and um...stalled...
I then drove us back to a quiet estate. I felt very, very flustered, scared and overwhelmed....which is probably what caused me to fluff everything I know how to do. At every SINGLE junction I then came to...I stalled. Stalling was not exclusive to junctions, nor was it limited to one stall per junction...at one point I had stalled six times in one turn. I then missed turns at roundabouts, and drove round one with my hand on my horn since I'd slipped and daren't straighten my hands to stop the horn in case I drove off the roundabout wrong.
So it went VERY badly. And I'm so scared and freaked out I'm not sure I want to learn to drive now... I am aware I might feel better next time we do it, maybe it just surprised me and freaked me out. Still I'm feeling pretty traumatized today, and sleeping on it hasn't improved my mood.