First of all, Good job on your 67 lbs gone!

As you lose more, it'll start to show for you when you look in the mirror, probably at about 240-250.
I agree that you should start taking a pic now at every 20 lbs lost. It'll help your mind to see the gradual changes if you capture it in a pic. When you get down to near 200, then start taking pics at every 10 lbs lost. It really speeds up the changes when you get down further.

But, most of all, do not get discouraged and quit! You are doing extremely well! Keep up all your hard work and you will see changes!!