The trouble with fighting fears is that you can scare yourself so much that you confirm to yourself that the fear was justified!!!
A gentle approach will work better here. Go flying by yourself, but initially do something you feel comfortable with, maybe just some circuits. Next time, do a short local flight, and as Genghis said, prepare thoroughly. After that, go as little further, to the east where there's no controlled airspace. Work up gradually, but do ONE new thing at a time, not half a dozen. Want to track a VOR? Just do that; it's enough for one trip. Don't plan a new route and go into controlled airspace as well. Get the idea?
What you're experiencing is normal for a newish PPL at a new airfield in a new area close to the crowded airspace of London. When I first qualified I didn't dare fly out of anywhere other than my home airfield, I was so scared. It'll get better. Other people feel that way too, I'll bet, but it's not done to admit your fears in many flying clubs.
Good luck and try to have fun.