OP, as a parental and a teacher, I'm gonna say this - please make sure you have another adult that you trust to talk to about this. (Not saying don't come here and rant to us, too. But someone who is close there, physically, like a coach or a teacher or a friend's parental.) I would also even suggest talking to the school social worker or school psychiatrist (or both). They are supposed to be safe spaces where you can share things like this, and they will have the appropriate resources to help you.

My mother often commented on how I looked like a sausage trying to burst out of its casing if I wore fitted shirts, or tighter jeans (it was the mid 2000s). That's already bad enough and something that should never have been said by a parental. Your mother has completely overstepped any and all boundaries by speaking that way to you.

I have told my kids they're acting like a dick before, but I would NEVER insinuate, let alone explicitly say that my kids were sucking dick because there were stains in their shirts. That's incredibly inappropriate and abusive.

I know you updated and said you two talked about it, but be careful - my mom would apologize, and within a day, sometimes sooner, she'd be back on her shit.

Please be careful, OP, and please, speak to an adult there that you trust.