Nikki

Obviously I can't diagnose you but feasting and fasting does constitute an eating disorder and you should seek proper help to break the addiction (because it is an addiction or compulsion).

When a person tries to live on starvation rations, the body will rebel after a while and try to take in more calories, hence the bingeing. It's a survival mechanism.

You did not say whether you purge or vomit after a binge.

Your weight is low, but not ominously so for your height and any diagnosis would also depend on your type of build.

Please do consult a professional who can assess you properly.

You can beat this, NikkiB

Best wishes, FG