How Can Chronic Depression Be Treated?

As its a Sunday and can t phone my GP , have had episodes of depression before and been free off anti depressants for Two years , the past three months my health has been very up and down and I m beginning to think its anxiety. Or stress related , my bowels are bad and i haven t had my normal period in 3 months, GP tested for everything all results came back clear, I decided to take my mums prescription of citalopram 10mg took one yesterday afternoon bad nights sleep very anxious but I wanted to sleep had an awful nightmare to , took another this morning and my guts are gurggling like non stop and my nausea is terrible I have forced my self to eat I m just wondering what else I can do to start motivating myself and not feel so tired?!