Struggling to get diagnosed with POTS

Trying to get diagnosed with POTS.. The cardiologist at OSU suggested that I have it but he said that he didn't know enough about it to completely diagnose me and then he ordered a 30-day event monitor that im wearing now... I've been blown off by so many doctors as saying it's all in my head that it's all just anxiety... I've had symptoms of this probably since 2017 or 2018.. I'm just afraid if this heart monitor comes back normal that the doctor he's sending me too the electrophysiologist will just go with every other doctor and say that there's nothing wrong and it's all anxiety.. My health care system had a tendency to blame everything they can't seem to figure out on mental health... If its anxiety, then why does my heart go nuts when I stand up, why does it go nuts when I sit up some days? I can feel the blood drain from my body, and I can feel my heart like drop to my feet and that's my less than a minute warning before I get really close to passing out.. I know anxiety, at least I know my anxiety , and mine doesn't affect me like this... I don't think it's anxiety, and neither does the first cardiologist I saw