Hi Gerry. Discourse is supposed to save a "draft" for you as you work on a post but sometimes things in browsers can be a little flaky. But it would be worth clicking this link below and see if your "draft" is still there for you. It would popup at the bottom of the page.
I also went in our database and found something that might be the "draft" you were working on. I'll copy and paste it into an email for you.
(When working on really long posts, I've always found best to copy and paste your work into Word or a text editor every once in a while to save it to be safe. Or work on it in Word or a text editor and then copy and paste it into the browser.)