Reflections,
Your devotion is admirable
Do you think that the Church requires you to fast like this? Fasting is defined by the Church as one full meal per day with two smaller meals. The only days where this fast is required are Ash Wendsday and Good Friday. What you describe below is not fasting. Doing that for 40 days, espically is you have a history of an ED, is not a good idea.
Instead of fasting from food, it would be a good idea to give up something else. TV, Internet, etc. Think about where you spend a lot or even too much time. What we give up for Lent should be something that keeps us from God. It doesn't sound like that thing is food for you.
You can find other details of the lenten requirement on-line (Google Lent/Catholic, newadvent.org and others will have information).
Good for you going to daily mass- that's a great Lenten devotion.