Coming off of anti-depressants please help!!!?

i have had depression for a number of years now...im not down about it but it was hard to admit and i started anti-depressants about 2 months ago...for the past few weeks my sister was transferred to abroad for a month and im looking after my child (18 months) and her 3 older children...i forgot to take the tablets with me and for the past week i haven't been to bad but yesterday i broke down and felt VERY irate!!! i feel extremely tired and now feeling nauseouss and sick...what do i do do oi start taking them again?? or do i let it wear off...or am i going to be like this forever?? i feel terrible :( and keep snapping at everyone :( please help!!!