There is no way you or anyone is alone with these issues. I've struggled with depression in various forms since I was 7 years old, which is the year I became suicidal, really and truly, for the first time (but hardly the last). And after that, because child psychiatry was so primitive at the time, I wound up being a psychiatric guinea pig for two years while they tried every drug on the market on me, most of which made me worse, until they finally thought of putting me on lithium. When that worked, they realized I had bipolar disorder (later amended to schizoaffective disorder, bipolar type when my problems turned psychotic in my early 20s). After that, I was mostly ok, but I had to deal with the memories of the nightmare I had been through, during which due to both my own symptoms and the results of the various medications (and medication changes) I was on, I was very simply not myself. But IMHO, as difficult as that was, it was ENTIRELY justified, because I was very serious about committing suicide when I was 7. People try to tell me that children are not capable of suicide, but they're wrong, they're very, very wrong. A child doesn't have to understand life to know that they're in such pain that they would consider ending their life, and all it takes is one attempt sometimes for them to succeed. (This is why I am now studying for a career in social work so I can be a therapist for children in these kinds of crises).
It got much, much worse again when I was a teenager, and I developed extreme neediness and loneliness and desperately worried all the time that my closest friends were going to abandon me if I made the wrong move. The fact that they never did, after all I put them through, shows that they were true friends. After high school, as I said, my depression was compounded by psychosis, and it made me disabled (I never LEGALLY tried to qualify as disabled, but I'm convinced if I'd tried I would have-schizophrenia can and does disable people). I attempted suicide multiple times, was hospitalized 5 times over the course of 2 years, and had 18 electroshock treatments....which, I am convinced, are the reason I am alive today. Those treatments made it possible for the first time since I was 15 to even imagine a career, or school, or indeed anything but life in a hospital (which is where I was headed). They were terrifying, and they had some side effects I still deal with today, but they saved me. That was three years ago, and while I still have bouts of depression (more these days related to hormones than my mental illness without a doubt, though, if that's not TMI!), it is never as bad as it was, and I'm convinced it never will be as bad as it was, now that I've had my second chance. (And that's what I really feel like it was-a second chance. I started college at age 24, after most of my friends had already finished it, and I feel like my illness caused me to forfeit my chance to join them when they started-and I feel a lot of pain about all that time that I lost when I was sufferring so badly-but these days, I'm not the kind of person who dwells on her losses).
Psychiatric treatment can be really difficult, and it's not perfect, but I am living proof that it saves lives, when they get it right-and I think that most people, if they don't kill themselves first, will get it right eventually, with the right meds and treatment and so on. But surviving severe, chronic, and treatment-resistant mental illness has changed me as a person-a better person.