agree with the majority on this one, when I got back into bikes after a layoff I had similar situations and considered further training, but in the end I never bothered, just rode my bike as often as possible and stopped worrying about if i was fast enough etc. As an exercise though i would say pick a familiar route and ride it as often as possible, start at a pace that you are comfortable with but relax and concentrate on being smooth. As daft as it sounds talk yourself through the route, eg. corner coming, easy right hander, push a little more on the bars this time etc. , its a bit weird but really you are just doing what a trainer would do. The more you ride the route the more smoother you should get and you will find you are probably going quicker than when you started.
also definately put up if you are going for a ride on the site and hopefully you will get some willing riders to come along, don't be worried to tell them about your lack of skills or what is really a confidence issue, everyone I'v ever met through this site has always taken abilities into consideration and is more than willing to give advice and help.
I'm still no where near as quick or as talented as some of the guys i ride with regularly but its brought my riding on leaps and bounds, so don't be afraid to post a ride or tag along with any posted.
Mostly though just enjoy, stop stressing and things will improve straight away, as Smiler said if we were all that great we'd all be World Champions ;)
