Emotional Breakdown

Hello,
My concern is for my husband. He is in his mid fifties. Last summer he was reunited with a son after many years of being apart. That was the beginning of the depression. For the first time, I saw my husband cry... over things that had been in the past, old feelings that he had buried inside himself. His emotions swung between happiness and regretful depression. Then as the weeks went by, there was more crying and some unbalanced thinking. He was feeling like a teenager again. His sexual desires were very greatly increased. But the depression was overwhelming. He cries so frequently now that I am worried he will have a breakdown. He has also lost weight, and he was already thin. We have been married for a very long time. All these changes are so out of character for him. Please help if you can. I can add more information if it is needed.
Thank you!