It rarely does lead to self-harm.
What results in self-harm is personality disorder like borderline personality disorder with specific personality traits.
I am more asocial. On anti-social spectrum spending major portion of my time on the internet and doing random stuff only I enjoy...
But I get these borderline features too.
It's very complicated with personality disorders if you look at it. You feel like a psychopath, then you feel like some paranoid fck, then again you feel like destroying half the city, then you drop like from a building and feel like you just did the worst thing ever. Then it leads to depression and drug abuse or bad relationships.
These are multiple cycles running in cycles within cycles...
Pure depression is something you might have cause you say you've been doing well all your life. I don't have just pure depression. My depression stems from my insane ways of dealing with the world, living with extremely negative people / whiners and anti-social people. And my thoughts I learned in my environment translate to emotions, then bad (or sometimes good) actions which then it fcks (or fixes if it's good) my neurotransmitters from overwhelming negativity and hatred (or positivity and love)...
Your behavior and thinking have huge influence on your neurotransmitters basically.
Anyone is doing their best, but everyone can do better. Even saints!
Don't tell me a very positive person wouldn't be able to influence you day by day and take you out of that hole.
I just don't believe a huge amount of trial and error wouldn't help.
Sometimes it's the case but if you had somehow good things in your life, there must be some way to influence that beyond meds.
I find some experiences so rewarding I don't feel like getting depressed again. And they all are in groups, with close connection, bonding to other people.
I heard having kids can change your life...
Why would your career make your life less depressed? In fact it does the opposite for me. It's more stress, responsibility. It's burning me out.
If you think about your body and brain: does it care about itself or bank account status? For sure it cares about itself. Putting constant stress on it like career / engineering is basically too hard.
If I don't get to meet very positive people, no job satisfies me. In fact at jobs all I care about is nice people, not even money.
Maybe don't chase career and status next time. Balance it with relationships.
I would practice as much self-care and self-help as possible instead of practicing adding another 0 to my bank account number. Don't confuse it with self-improvement - you want real, science based psychology and therapy.
I read "psychologytoday" and books for behavioral therapy to understand how to take things easy.
In other words, you want to remove depression by making money or getting more clients? You'll get the opposite effect. My experience.

Money is just a medium of energy. You don't need too much of it to meet people and live life as it's supposed to be lived.
The only thing you can multiply forever are emotions. You give love to someone, they give back to you. And it doesn't cost anything but being with each other.
What do you multiply when you're alone? Boredom. If you're too bored, you'll freeze. And you'll not want to move.
If you get love, you'll get hot and aroused. Multiply this and you'll be feeling like a 7 year old kid seeing new car dad just bought you.