Replying to own post ended up deleting the original

So I recently needed to leave a lengthy notice to deal with interpersonal problem with an alliance. Well some new info came to light but when I tried to edit it and add a PS it went over the character count. Simple fix, I'll just reply to the original, only when I did I made a mistake because it was not replying it was editing and it wiped the original. And I can't find anyway to bring it back. First, either take away the reply option to our own posts or allow self replies. Either is fine, but this system is just asking for problems like this one. Second, maybe give people a one off undo on edited post to get back if you have an accident. don't need a long undo list just an oh that needed to be what it was.