Pain, bruising, and lightheadedness

Hi! I'm 15, a sophomore in highschool, and I'm not currently diagnosed with any physical conditions, but I suspect I have something along the lines of POTS or EDS. I've done my research, though many assume I'm very uneducated on everything serious due to my age, and I'm aware my symptoms are not normal and align with both. When I stand up, I feel faint and lose my vision, which I'm told could by low iron which I'm aware of but that's not my only symptom. I dislocate joints easier then most, I can overextend most of my joints, I easily pop my kneecap in and out of place (it's an unconventional fidget), I bruise super easily, as in resting my elbow on my hip for 5 minutes and bruising, and salt helps when I'm lightheaded and the heat makes it worse. I have chronic joint pain and chronic back pain (both not technically diagnosed but that's not exactly something you need diagnosed to know), and asthma. My question is which one do I have? Do I have both? And how do I lessen my symptoms as much as I can? Sorry for the long explanation, I just want all the information out there.