Extreme mood swings and irritability

I have been seeing my boyfriend for over a year and have noticed some very strange behaviour patterns. Extreme mood swings, irritability, binge eating completely under weight, self medicates on drink and weed, refers to himself as roger on a good mood rog on a bad and rogete when feeling extremely confident about his self image. He is very aware of his self image and will only wear black or white. For a whole year he only wore jeans and a white t-shirt and has recently shoppedfor a whole new wardrobe. His sleep can be up and down and I have noticed his breathing is very heavy and rapid. He'll say things sometimes without being aware of what he saying and the words can be very nasty. Because he drinks and smokes so much it is hard to say what he is like on a normal mood. He exagerates when ill and does not stop going on about the illness. he went to the docs and was diagnosed with acute bipolar and prescribed anti depressants. I suspect he is lying to me! can you advice me please?