Is my father going through a mid life crisis? :/?

Many men become depressed at age 50. They see life starting to pass by very quickly, they are getting physically weaker and they brood about what they haven't achieved in their life. It's normal. The relationship with the family can deteriorate as he can see his failure mirrored (rightly or wrongly) in the images of other family members. He may need counselling. If there are money worries then this will make things worse.