Don't feel bad about the dating website...and don't overanalyze your decision there.
One of the things about a message board like this is you WILL get advice from both sides of the coin. Some will tell you that if your W walks out that GAL includes dating or finding someone else. Others will tell you that's not the way to go. You must decide for yourself.
You can tell her you were on dating website if you like, but I'm not sure that's the big issue here. If your W knows you want to reconcile and she knows YOU.
Again, I wonder if your W doesn't view you as a big worrier and that has worn her down. Can you start to show her you are changing in this area? Can you change in this area? Am I way off base?