Mark
You don't have to feel guilty. I know that you want to, but I think that you need to hear this. Please don't be angry. Please.
Megan could have died any day. I could, you could, Wayne could. We never know when we're going to go out. What I do know is that if she saw you like this, she'd be more angry at how you're slipping up and stressing out. We were children, love. Sometimes things happen. You didn't cause any of this, outside of your relationship. I think it's time to accept that and forgive yourself.