How do I brace myself mentally for whatever happens next?

If you really want to let go you should stop any connection between the two of you after your break up. That was almost 2 years ago right? I know it is so hard to forget but if you did that during those years maybe there is still love left but only a little because it is normal. You may have move on if you did that. But still you hold back the past. Thats why you're expecting something. You said that you already got your closure but i guess not(just my opinion). And if you failed again, do stop any connection. So if the day comes you'll act now as friends and you'll not expect again. Sorry for the harsh opinion but i hope it helps! Good luck:)