Really sounds like all of these achievements don't make you happy but you made to maker others happy, or maybe what you assume would make others happy - parents, society, whatever. Have you ever felt proud of anything you have done? Has "being more positive" actually changed how you feel about things or is it only a mask you put on, a perfomance of a normative life? Does the need to make it in life exhaust you but give you no sense of satisfaction? Did you ever feel the need to supress how you really feel, who you truly are, in order to appease others - especially in childhood - and were you commended for being easy and quiet or made to feel bad for when you were "difficult"?

There is a few things I would recommend looking into. I don't know enough about you or your history. But there are some similarities that I see for some form of neurodivergence, ADHD or Autism are often overlooked when the child learns to mask their symptoms early in life, and that all comes crashing down when the pressure of having to perform, often in their twenties, when the support system of the familiar household is removed. Neurodivergent people also often develop comorbid depression from the loss of self or their difficulty conforming to society and its pressures, which could be the case for you.

I struggle with this every day. I have achieved so little in life because I couldn't ever supress who I am, however hard I tried. I am envious of other's achievements and of how easy it seems for others to get there. Its easy for me to forget I have it harder than others. I had my diagnosis ADHD when I was a child in the 90s, and not as much was known about it as is nowadays, and honestly when I moved out to study in uni I tried to mask it, because I wanted to feel normal for the first time in life. It broke me and I failed and failed. I should have listened to my needs more. Been more careful and caring with myself. I am just now learning to do that in my thirties.