when he posted we were back together on his social media he had tons of people come out of the woodwork to tell him not to take me bac and I was a worthless woman that deserved no rights

See here’s the thing: a person who is able to rationalise something morally unjustifiable once, will be able to do it again.

By cheating you showed everyone you have no real spine to speak of, you can rationalise it all you like (that’s part of the problem) but the reality is that when you had the choice to break up and pursue the other person or not and cheat, you managed to talk yourself into accepting betraying the supposedly most important person in your life.

Moreover, there is absolutely no way for you to ever prove you won’t do it again until you die, and even then some people will still be skeptical even if you never do it again, and they’d be correct to be.

You may have grown a sense of respect for other people’s trusts, or you may have gotten better at cheating, or your boyfriend may have settled for a serial cheater and decided to turn the other way.

Either way they are trying to spare him from this AND to prevent society at large from accepting cheaters back into relationships because nobody, not even cheaters like you, wants cheating to be done to them, and making it something you can come back from makes it more likely.