Looking for advice on POTS diagnosis and specialists

I'm fairly certain I have POTS. I've done a home test and have pretty much all of the symptoms, so much so that I have to use a cane for balance due to lightheadedness and dizziness when i stand up. Some times if i dont sit myself down quick enough I get to the point I feel like I'm on the verge of passing out (its happened many times before) I'm waiting to get a call back from the cardiologist I see and Im looking for any tips on what specialists (other than a cardiologist) I should see? I've heard horror stories of cardiologists not believing people and such Also any tips on things that help/relieve these symptoms would be amazing. thanks everyone:')