If you look at the pre-agricultural revolution genetic data, 17 women reproduced for every one man. What ended up happening is that one man asserted dominance over most of the others, fucked all the women, and those women became single moms raising the kids on their own. You see this behavior in peacocks, other mammals, even chimpanzees, whom we share 98% of dna with. Additionally, there's an entire reddit called "BlackPill Science" which posts peer-reviewed studies analyzing human sexual behavior.
This arrangement is not socially stable, because men are really horny and want to reproduce, leading to mass lashing outs of violence, death, and rape, because most men want to be the one chosen by the woman. Pre-agrilcultural revolution world was a hellhole.
With the onset of the agricultural revolution, we made a compromise. If a man proved his worth and showed a certain level of dominance to win over a woman, he would pledge loyalty to her and help her raise the kids. This meant less sexual satisfaction for women, but it ensured the offspring survived and men were civilized and calmed down.
However, our biology hasn't changed. Our ancestors created religion and stories of love and romance in order to enforce this deal. Saint George the brave handsome knight conquering the dragon and winning the princess. Odysseus conquering worlds while his wife, being constantly suited, pledged his loyalty to her love. Snow White and the the prince saving her from death. And we created moral systems that restrained female sexuality for this reason - not only are women not as horny as men and can deal with less sex, but it also made men feel like they weren't subpar and angry.
Unfortunately, our religions died. And the stories died. And female social shaming died. And now female sexuality is unrestrained, such that most women don't desire most men until the need for marriage arrives, at which point she uses you for your resources. If you enter into a marriage, you will never be desired as the man she once really truly wanted to fuck, you will never be loved, and what will likely happen is the woman will divorce you and steal half of your shit.
The blackpill is internalizing this reality and recognizing this. Assuming you can make at least 70k a year (which you can do even getting a community college certificate) by your 30s, most here can get married and have kids when settling time happens for a woman in her 30s. But it's a raw deal and not worth it. Also, Pandora's Box is opened, or perhaps Eve took a bite of the forbidden fruit. We know how female sexuality works now, and we can't unlearn it through myths and superstitions.
Women don't desire you, and won't. Ever. Maybe 100 years ago, but not now.
The blackpill is recognizing that we are in a collapsing civilization where animalistic impulses reign supreme, and there is nothing you can do about it besides acceptance.
The only thing I recommend is finding some source of meaning in your life. For me it's believing in reincarnation, that there is some purpose behind me experiencing this shit. Maybe my deity wants me to experience this to grow so I can mature up and be with him once I'm dead. That I can be with him, laugh and joke about the absurdity with it, and I can sit in his royal garden enjoying the sunshine and experiencing love.