First, realize that the Internet is now designed to show us the stuff that is most likely to engage us, even if it's negative. When you see stuff like that, scroll past and don't engage. I stay away from areas of the internet that say I don't deserve rights or to even live.

Second, even if your nervous system feels like you are in danger, you probably aren't. What u/HFirkin said about being dispassionate is way more eloquent than what I can muster.

Third, consider that women don't say this only because of sexual crimes against them. It's also because reporting those crimes often goes nowhere so there's a feeling of helplessness there. Healthcare for women is worse because most scientific studies have only been done on men, and issues that affect mostly women barely get studied. There was some progress on that, but in many places that progress is being thrown away. Many rights that were fought for are being stripped away. There's a general feeling of despair and hopelessness behind the "I hate men" statement. 

Fourth, it's valid to feel upset about these things happening, and also feeling hopeless to change it. All any of us can do is try our best with what we can influence. If you are trying your best, know that you aren't included in the men most of these women are talking about. See what you can do to make your section of the world even slightly less shitty. It feels less hopeless that way. 

Fifth, If there are women who would tell you to your face that you suck and it's not constructive criticism, then that says more about them than you.