<human>: Can you give me a shortened version of the text?

So my ex and I broke up only a few weeks ago. The breakup was a little rough for the both of us and things have been mending slowly since, but I recently found out that he has just started casually dating someone new; I would never have known this had the girl not tried adding me on Instagram and putting his name in her bio. Naturally, I looked her up to see what she was all about. Her Facebook page is absolutely vile. She spews racist garbage left and right, calls girls "bitches", "sluts", and "whores" for all the wrong things, and is overall, incredibly problematic. I've seen several posts in which my ex has called her out in the comments for her racism and ignorance, yet he still somehow chooses to go out with her?

I know that if my ex is seeing someone like this, then it probably shows the kind of person he is and that's not someone I ever want to be with again. But I just can't stop thinking about it. We've dated for so long and I thought I knew him well. I knew his politics, his values, his morals and personal beliefs and all of that conflicts with the kind of person he's seeing. Perhaps he doesn't care and is only in it for the sex, or whatever it is, but the constant thought running through my mind always is: How could he leave me for someone like *that*? How does he stomach the racism and the hate and the garbage? I keep asking myself this and it's killing my self confidence. I know I shouldn't care, but I can't help it.

How do I get over this shit?
<bot>: recent ex has started casually dating someone new. She's incredibly racist/homophobic/problematic and it's killing my self confidence to know that he left me for somebody like that. How do I move on from this?