I think you are worrying too much. I've found that, most of the time, people don't take what we say/e-mail in the way we think they will. So stop agonizing. There's nothing you can do about it now anyway, that e-mail has been sent.

If you want to go to the service, then go and go for the memory of the person who has passed. If you don't want to go, send your condolences and stop worry about it.

In my experience, I didn't remember much of what happened in the weeks following my parents passing. I know many people were very kind and sent their condolences, but I couldn't tell you who said what. So, don't fret about this so much. You're just stressing yourself too much over this.