Jet-
were you down 10 techs to none or did you have anything to trade?
the key in this type of game is to go deep into the tree in one path--keep going until you have something to trade.
Of course the AI will have way more tech since you haven't been able to trade yet. In my game I was down about 10 net techs to the first 2 AI I met (and I don't think they were the most advanced). However, I had 2 techs on them--paper and phil. So I traded initially for compass, MC, mach, and calender + gold and maps. Then I bulb edu and when I'm almost to lib trade for all the rest I need--monarchy, drama, music, feud, guilds, banking, eng, optics, and even gunpowder. So instantly I'm caught up and then I get lib--astro and am even with the leaders.
I also settled 2 eng and I think 2 sci--I only burned an eng on the Glib.