I wrote a question the other day. It was very detailed, but I couldn't post it because I had posted another question less than 40 minutes prior, so I decided to exit. It asked if I wanted to save it as a draft, and I said yes. Now, I can't access the draft. How do I access my drafts?
If you use the app there is a specific button to access saved drafts on the left slide bar. I'm not sure if it syncs drafts with other devices though.
It may be that you've managed to accidentally delete your draft, I'm guessing it's stored locally on your computer using cookies or similar so if you cleared them your question may have gone too.
You could try and ask your question on the stack exchange meta site. There are people there that have a greater understanding of how Stack Exchange works.