I Was Diagnosed With Hypersomnia About 1 1/2 Years Ago

I was diagnosed with hypersomnia about 1 1/2 years ago at the time I was diagnosed I was not depressed although I have had depression in the past early 40s. at first the meds seem to help and after a few months they stopped working . I wasn't getting much help from doctor. so I got a second opinion . the doctor is very helpful and understanding the meds help some what but my understanding is that this is something ill have to deal with. past 3 months my jobs giving me a hard time im trying my hardest to function a normal life but I feel like no matter what I do I cant get a grip on this. How do you know the difference between depression and hypersomnia. again I was not depressed when first diagnosed