“But you don’t seem depressed”

I put a pretty good front on, I’m happy most days, I can be perfectly content then the depression and anxiety creeps in. It’s overwhelming and I have that little voice that says “everyone would be better off if you weren’t here.”I struggle silently with depression, my husband doesn’t understand it and think it just self pity or people that are “weak” minded and maybe I am weak minded. I look happy to the outside world but my world on the inside is chaos. It’s getting worse and I don’t know what to do.