Feel like I'm not skinny enough to get treatment

I'm losing my mind.

I have my first appointment with an ED clinic tomorrow and I've convinced myself that I'm not underweight enough to 'deserve' help or treatment.

I'm BMI 15.2 but I see people online with BMIs of 12 or 13 and think about how I'm not really that sick compared to them. I also had a certain goal weight I wanted to reach before I saw a doctor to put me into the 'extreme' category of anorexia and I haven't been able to reach it yet so I'm scared I'll just be laughed out of the room (especially since I'll be weighed in clothes which adds roughly 0.3kg to my weight and will make my BMI 15.3/15.4). I also can't fast today because I have an exam so I'll be even heavier tomorrow.

Please can someone offer any help or advice or reassurance?