My parents want to come to my hrt appointment

I (18ftm) am going on testosterone and my parents are mad at me for not letting them into my appointments with my doctor. I let them in for the first one and it was okay but I genuinely didn’t feel like I could be honest with my provider when they were in the room because despite the fact that it could be worse they aren’t the most supportive. They aren’t kicking me off the insurance, kicking me out, or threatening to like, not help me pay for college but every time they open their mouth or I try and talk with them about it it becomes obvious they, at least at this point in time, care more about me being their daughter then the fact I’m their kid. At least my mom does and my dad always takes her side.

I told my dad that I didn’t want them at the appointment because I was uncomfortable with my parents being at my medical appointments but then in the middle of it my mom texted asking to come in and I told her no but I’d ask her questions for her and relay the answers, which I did. And the entire time when I was answering her questions she kept being like “but you’re not a doctor” even when I was relaying the information verbatim. My dad later yelled at me about not letting her in despite the fact he said he’d respect that I didn’t want them there.

They also want me to start therapy again (which was planning to anyways) but they’ve become extremely aggressive about it to the point where my dad said “if you don’t we’re going to have problems” so now something I wanted to do for myself is a looming deadline to get my parents off my ass and considering how nosy they are about my gender they’re probably gonna keep asking about what happens in the appointments.

I know I’m lucky that my parents aren’t worse but I don’t know how to diffuse this situation, especially because I’m so financially reliant on them.