Is this acceptable?

[SharpUmberDeer]

I’m 18. Living at home. My mum just found out I’m having sex with my boyfriend. She hit me across the face and called me names. Then made me go with her to the doctors to be tested for STD’s. I went as I felt so awful and she’s very hard to stand up to. She’s banned me from seeing him.

No, absolutely not acceptable and in fact domestic abuse from your mother. She's assaulted you. You're an adult, you can make your own choices on these matters.
Any advice would really depend on what future relationship you want with your mum, but I think a long and difficult conversation needs to be had with a safe third person present.

That's a lot to happen in one night.

I’m surprised the gp sanctioned STD tests on your mothers say so.

It’s not acceptable. I’d leave.

What suggests to you it was all in one night?

Jumping to a strange conclusion there, with that sketchy reading comprehension.

That’s abuse. You are an adult and should be treated as such.