It's good that you are questioning things, that's how progress takes place. Personally, I'm not a fan of phrases such as 'You just have to deal with things' and 'You'll be right', seeing that such comments provide no form of management strategy when it comes to moving ahead. And, yes, chronic depression is very different from the average down day, seeing that one of the greatest challenges faced in depression involves not knowing when it will end if ever. By the way, I'm one of those people who did see my depression come to an end, so freedom always remains a possibility.
When it comes to career, one of the best pieces of advice I've ever heard is - Don't ask 'What do I want to do?' Instead ask 'Who do I want to be?' Deciding who you want to be may give you a clearer sense of direction. Do you want to be a hero - firefighter, police officer etc. A leader - teacher, politician, etc. The list goes on in regard to possible identity. Who did you want to be when you were younger? Did you love writing, painting and so on? Did you lose sight of yourself/elements of your nature? Anyhow, it's a bit of food for thought. A clear identity provokes passion.
Take care of yourself BlueArt