Dark And Oily Skin. History Of Bipolar Disorder. Need Medication

my skin was fair and i had normal skin but since 7-8 months my skin has become really dark and oily so that you can see clear difference between other body skin. i had a history of bipolar disorder and have been takin alporic acid aka dvla , Intalith Lithium and bupron anti dipressent i stoped takin them from 3 months but i took them for a year before that.I have also taken orlistat anti obesity pills. now i am on medication of multi vitamin multiminerals and ntioxident tab called NUTRAMIDE and as my skin doctor asked me to get bloodtest turned ot i m animic to b12 so i take methyle coblamine injections as well my doctor asked me to take cholecelciferol sachet for vitamin d-3 once a week and prescribed me hydroquinoon which i stped due to swelling and redning of face. stil i believe treatment is not effective my skin is literally dark and it has been almost 2 months since i m on medication for skin.