My daughter was diagnosed with WPW two years ago and also had an ablation. Everything went fine - let me give you some backround.
There are different types of WPW, the main distinction is whether or not you have ever had a "blackout" during your period of rapid heartbeats. Another is based on the direction the charge - a backwards/retrograde direction is more serious then a forward/anategrade direction. In my daughter's case, she did blackout, and had the backward charge direction.
The procedure itself involves putting a very thin tube, a catheter into a blood vessel in your groin. From that entry point, the cardiologist will snake this tiny tube - sort of like a plumber snakes a pipe - following it all the way to your heart. It will then enter your heart and electronic sense the location of your heart nodes. (The node releases an electrical signal to get your heart to "beat"). WPW results from having an extra node - so sometimes the heart gets these extra signals to beat, causing the heart to beat very rapidly - you've probably felt this yourself. When this tube/catheter locates the extra node (we're talkin' about a piece of heart tissue the size of this letter "O", your physican will press a button to send out some heat to burn the node. Scar tissue forms, and your heart goes one beating regularly.
My daughter had this procedure done on a Friday, and was back in school on Monday. Three months later we hiked the Grand Canyon togehter. She spent one night in the hospital - which was actually the most difficult part for her, because you have to lie in bed without moving/raising your legs. There was also some irritation around the spot in her groin where the catheter went in.
The main point is that the procedure has become fairly routine and common at this point in time. I've since met several other people - one your age - who also had the procedure done. To this day, my daughter doesn't think of the ablation as being such a big deal.
Talk to your cardiologist. Ask him or her her many of these procedures he/she has done. Ask him/her to describe any problems they have encountered. And remember - you have an extra bit of tissue on your heart - but YOU DO NOT HAVE HEART DISEASE. Unless you are told otherwise by your physican, you have a young, healthy heart. The heart is an extremely strong muscle. Do your research - there's lots of stuff on the web - try to relax, and don't worry about the ablation. The risks associated with the procedure are lower then the risks of WPW if you've had blackouts. Good Luck!