Should I stop playing now?

Start again with an alt account.

Print out the screenshot, frame it, put it above your fireplace, install a spotlight, direct said spotlight at the picture, bask in its glory on a nightly basis.

Add one more 9 to that

Looks low. Continued playing could fix that.

You have a screenshot, which is enough. Just keep playing.

I almost felt the same when I reached exactly 5.000.000. But then I thought, 10.000.000 would look pretty good as well, so I'm still going ;)

So try to get 9.999.999 :)