How long after onset of symptoms did you realize something was wrong and/or get diagnosed?

I've had POTS symptoms for as long as I can remember. I specifically remember being a teenager and having to lie down after showers, struggling to stand for a long time, feeling sick and heavy after eating. I never understood the people that would stand because it was "more comfortable than sitting." I've never felt that. Standing has always been so uncomfortable, but I just assumed I was lazy or unfit. There was a time in my life around 18/19 years old when I WAS fit but I hated working out legs because I always got sooooo dizzy and if I could do a workout sitting down, I would. I assumed that I wasn't eating enough or I was dehydrated. Pregnancy actually caused me to pass out multiple times. My chest has always been super tight and I feel uneven on my feet every time I stand. I thought it was all normal. It took until me being 4 weeks postpartum with pneumonia and a standing HR of 200+ for doctors to be like "hey something isn't right here" lol. Looking back, idk how I made it until 23 to even realize something was off. I always felt odd growing up but just blamed it on not eating enough or anxiety