tired and confused….

I am so tired and confused as well as worried and feeling sad. My partner of 4 years is living with depression. When we first met I had no idea. I knew he had had a very tragic life with losing 2 of his 3 children but he never mentioned to me that he is living with depression. The first couple of years I didn't pick up on anything. He worked away a lot and when he was home he was happy and energetic. He is not working away anymore. The last couple of years I noticed the change. He would go for walks late by himself, just take off and not say anything. It worried me a lot. He then opened up and told me of his life with depression. I have never seen him cry...not even when he was tellng me of the tragic events of his 2 children who both passed away at different times. I cried when he told me, it was heart breaking...I just held him and told him I was here for him. About a year ago he was not doing as well with the depression and his doctor up-ed his medication. That made a bit of a difference for a short time. We had way more good days, not alot of down days and when he had down days there were for a day of two and then he was his happy energetic self. We would go out a lot, socialise a lot, go dancing etc... Of late he is having more down days than good days.... He is still able to get up and go to work. At night when we get home he is just withdrawn, just plays on the computer or watches TV. No chat, no playfulness like he was in the past. Each day lately seems to be a struggle to do anything... He is sleeping more, pretty much sleeps away the weekends, eats more and has told me that he doesn't want the physical contact (he doesn't feel like it..he doesn't need it.), No hugs, nothing...Which is the complete opposite to what he has always been like. I am not coping with all this, he is not coping with this.... I have started to check if he has been taking his meds and I have noticed that he takes them for a few days and then he misses a day or two and then takes them and then misses them etc... I have gently reminded him that he hasn't taken his meds some days and he just gets angry cause he says I am checking up on him....He tells me he is 54 and doesn't need a Mother figure checking up on him....I don't know what to do. Is missing one day a problem when you are on meds for depression? Does this affect the depression? I have started questioning myself whether it is the depression or me? I am just so confused and feeling lost and helpless.....I really miss him, I really miss our fun, happy times together.