No of course it's not all downhill, or else I'd have blown my head off. I'm 63 and I feel pretty good. I've been depressed since I was a small child. Luckily I sought out therapy in my 20's and got rid of a lot of "baggage" that I'd been carrying around for years.
I think that would be a good idea for you too. Therapy is called for in your case. You really do need to see a therapist. Is that possible? Ii hope so because you do need to talk about your issues. Then if things continue and your depression doesn't ease, you'd need to be put on an antidepressant. You may be clinically depressed, but I doubt it. Please see a therapist. You won't regret it.
I wish you the very best. God bless and please take care. And update us on what happens, will you please. We DO care. Hugs, Lee