As someone's said before, it's a rite of passage to fall over wearing clipless! Usually, sod's law will dictate that it happens in front of a captive audience - bus stop, pedestrian crossing, that sort of thing; the more people spectating, the more likely it is to happen! Rule number two is that no-one will usually come to your aid and you're often left struggling to haul yourself from under the bike, still clipped in!
Sometimes, the best way to overcome fear is to fall off - you realise it's not as bad as you expected (usually!) and that you bounce quite well! I subscribed to this way of thinking lots when I first started out!
Once you build up your confidence, you'll never go back. Traffic lights and junctions are always a challenge - especially when you get over-confident and try to bunny hop without unclipping! Pedalling backwards when you stop buys you about 15 seconds!
Seriously, it's all about anticipation. Unclipping one foot before you get to a junction will buy you time as a beginner. Gradually, as you confidence and technique grows, you'll be able to judge when and where to unclip.
If your tension is adjusted properly, you should be able to unclip whenever you need to, even at late notice - and it goes without saying to unclip at the bottom of the pedal stroke, when the leg is extended - unclipping when your knee is bent will prove almost impossible and scupper your joints to boot. Sometimes you might have to though, in an absolute emergency.
Learn to unclip with your nearside leg first - right for you guys, left for us Johnny Foreigners! Falling towards the kerb will prove second nature - in all the times I've fallen off (save for ice, when you have no control) I've fallen away from the traffic - something in my psyche knows it's the right thing to do!
Good luck GenHawk - you've bitten the bullet and are good to go!
Welcome to the board too, btw!