want 2 do fast,used to be borderline anorexic....

hiya well first of all i will introduce myself.... Im 19 yrs old and i used to be borderline anorexic but i was never actually thin! I have always been really fat!!!! Im 5'4" and i used to be 159 lbs, i lost 50 lbs in 3 month by cutting down on my food intake so at my lowest i was 109 lbs which the docs said was too low and i had to get weighed every week to make sure i wasnt losing! So anyway i have been binging loads and am back up to 149 lbs....Dont shun me off as 'some ana girl that wants to go back to the way she was', and please dont tell me to seek help-i tried that and look where it got me!! Anyway im 149 lbs and im doin a Water Fast purly for weight loss and nothing else! But also i really feel euphoric when i fast, like nothing else matters in the world!! And everything feels right and perfect!! Anyway i have only done 3 days on a Water Fast and i used to drink diet coke but now i decided to do water only!! I am starting now...friday 26 march..1pm! My freinds are having a party for my on sunday so i will be drinking vodka (on its own-no mixer)will this effect me?? Is it necessary to eat just veggies before a fast or can i go straight into it?? xx Hutchie