I have been diagnosed with dysthymia which is basically a very long term depression. My psychiatrist reckons I have been depressed for 28 years but to a varying degree. I have had times when, by being aware of my attitudes and thinking patterns (combined with medication I have been able to have quite a good quality of life.
It's more difficult at the moment and currently medication doesn't seem to help, but there is hope that we can find ways to make more of our lives in the future. There's a lot of research going on into meds and therapies.

You mentioned maybe you only know people who are more long term affected. That is likely as, while the majority of people do indeed make a recovery from a depressive episode, you won't find them much in places like this or support groups as, by definition, they recover and move on so we're all more likely to meet the minority who don't recover so well.

I'm sorry to hear of your struggles and wish you the best of luck and wisdom as you try to find a way forward.