Cardiologist told me that I can't have POTS because I'm fat

So I went and saw a new cardiologist this morning. I explained to the nurse my symptoms and why I was there (high blood pressure, high heart rate, dizziness, shaking, chest pain, heart palpitations). She did an EKG and took vitals and they were all normal. So the cardiologist comes in and introduces herself and then asks me if my old doctor actually did a test for pots or just thought I had it. Well I hadn't had an actual tilt table test so I said they didn't do a test. She tells me that she doesnt think I have POTS and that this is just normal for girls my age (I'm 18). She explains that when you stand up the blood rushes away from your head which makes you dizzy and I just need to "pump" my legs for a few seconds and then start walking. She explained to me that it happens to everyone and I'm probably just anemic because of my periods. I explained to her that I'm not having periods and haven't for the last year because of my birth control. Anyways, then she moves on to tell me all about pots which I know because I've done research on it. She tells me that my blood pressure is normal and not low which happens in people who have POTS is low. She also tells me that people with POTS are skinny and I'm decidedly not (I weigh 145 pounds). She also told me that if I really had POTS then my symptoms would be worse (i.e., fainting). I'm so done with doctors at this point