Questioning my POTS diagnosis

The bottom line, does your body not like being upright (standing or even sitting upright). When mine srarted, it was abrupt. Within 5 minutes of standing, i was 170bpm and extremely short of breath and simoly had to sit down. Sitting down, actually reclining with knees up and I'd be okay in minutes. The more servere, the longer it took to recover. After the worst ones, after recovery stage, i actually had hours up to a day of NO SYMPTOMS. odd stuff. But if i never needed to get up from my reclined pisition, i would have No problems. Also had no life and couldnt maintain as we all need bathroom and food.