Feeling sad is not the same as having depression.
Sorry, I don't mean to seem unfeeling, it can actually cause more suffering than clinical depression. I know because I remember how things used to affect me before I became depressed, so I'm not trying to minimise what you're going through. It sounds tough.
I just had to clear that up because it's so commonly misunderstood these days that it makes it even harder for people with clinical depression to explain themselves.