I’m sorry life hasn’t gone the way you wanted it. Unfortunately almost no one’s life does, this is just a fact of life. Many things that seems to be promised or “owed” us turn out to not be, or to be struggles. Depression is very real, and really does require professional help sometimes to get out of it. So I would suggest getting help if you can afford it.

On the bright side, your life is far from over, 43 is still plenty young enough to have meaningful relationships and build a career if you want to, it just requires that you out yourself in the correct situations repeatedly. You can still get married and have children if you want, you’re definitely not that old. Many people move on to their second marriage at your age.

I would suggest, that rather than promising yourself radical change each night, promise yourself one small change that you’ll make tomorrow. Just a single thing that will make your life better. It can be as simple as going for a walk or cleaning a single room. Do it first thing so you don’t procrastinate on it all day, banking an accomplishment each day is small and easy, but when you look back at a month of that you’ll have accomplished a lot and you’ll start to have a habit of doing things.