First Doctor's Appointment Anxiety

I have my first doctor's appointment in 4 hours. I haven't been to the doctors since we switched and I'm really nervous and I want to cancel but I can't. I need this appointment but it's so nerve-wracking. My body heats up and I fidget with my clothes. I can't make eye contact and unless its something really personal, my mom usually tells the doctor what's going on. I'm an adult age, I should be acting like one but I'm really scared to go tomorrow. I haven't been doing anything proactive/productive since we switched and I know I'm not health. I know what my charts and the scales are gonna say and I'm not ashamed as I haven't been trying but it still hurts to know I've fell so far away from my goal.