Throughout the 4 million-year history of mammalian evolution, those species and individuals who exhibited the greediest most selfish brazen behavior have been the ones to eat, survive, and breed. Generosity and other socially beneficial behaviors were not the norm. A sabre tooth tiger that gave his pray to another tiger didn't eat and didn't survive. It's only when there is a rampant surplus that organisms become philanthropic. But that was rarely the case, and certainly not the case in our current world.
It became such an important trait for survival that females of many species sought out the biggest and baddest mates to ensure survival of the offspring. There is still a little bit of that left over in us humans today: some women's desire for the "bad boy".
Your best bet is to make peace with the fact that honesty and kindness often bring no intrinsic reward other than how you feel about your own approach to life. When they taught you as a youngster that good always prevails and pious living gets you ahead, they were feeding you a load of horseshit. Living a life like Mr. Rogers may get you love and respect. But being an asshole gets you what you want and need. Think of the biggest assholes in the news daily; they're getting what they want (for the most part).
When you say you have nothing to show for it, that's not quite true. Maybe you have nothing tangible. But you have the satisfaction of knowing you have lived a kind life putting others before yourself.
The world is changing. It's heating up, and dying. Resources are dwindling. Those who have the means and the resources are grabbing all that they can. Ever see those news clips of frenzied people looting stores after a hurricane? That's what's happening now. The corporatists and oligarchs are squeezing and extracting as much value from the unwashed millions as they can before the whole system collapses. We are moving into a time of humanity where only the most driven will survive.
It's time for you to move into a 95/5 plan. That is where you spend at least 95% of your time working to your own benefit. Not someone else's. You don't have to be an asshole. But you can be a bit of a dick. Be a charmer. Pad up that resume with AI slop. Take advantage of every lead and opportunity. Barge your way through life and if you step on few toes in the process don't sweat it. Nice guys finish last.
The other 5% you can volunteer or be philanthropic, but never if it negatively affects your master 95% plan.
ps. happy birthday.