I STILL can't edit that post I mentioned 3 comments ago, and although I've so far had no problems with new posts, it leaves me nervous about spending a long time on posts in the future. Like people have suggested, from now on I may write them in Microsoft Word before putting them on the post to make sure I don't lose them.
I must say, for the first time I've used WordPress Support, I'm very disappointed. Over 5 days since I contacted them (albeit 2 of those being a weekend), and still no response. And I HAVE been checking Spam mail folders, so that's not the reason.