Husband thinks I’m overreacting

I’m 23yo and have an almost 2yo daughter. For her birth I had an epidural when I was about 7cm I believe ? Can’t really remember it went by so fast. I was in a car accident 9mos before that and my shoulder has been pretty bad since due to the seatbelt. Growing up, I remember constantly having heart palpitations. My heart rate would rise, I’d feel like I couldn’t breathe, I’d get lightheaded and hot flashes. They’d only last 15sec max. But they’d happen a lot and still do. Before I got pregnant, I brought it up to my doctor who did an ekg and found nothing (but ofc they wouldn’t bc they weren’t happening all the time, they’d be random). So I just moved on. But I’m not sure if what I’ve been feeling is normal. I get heart palpitations as always, but I also become winded when I do something as simple as crouching down or climbing up a flight of stairs. Our apartment is small so when I mop, I feel extreme exhausted and dehydrated almost like I did an entire workout but I literally just mopped. My back has been aching to the point where I can’t get up sometimes if I’m picking something up from the floor. I haven’t been to my doctor in years and I should probably go but when I brought it up to my husband he rolled his eyes and said I was being dramatic. That nothings wrong with me. But these don’t seem like normal things? I’m a SAHM and get plenty of rest, I’ll even take naps with my daughter some days. But I never have any energy to do anything. Sometimes I can’t even get myself out of bed because my body feels exhausted. We went biking this past weekend and after about 5mins, I felt like I couldn’t breathe, my legs kept giving out, and i started to feel a sharp pain shooting in my lung. Im not an active person, I hardly ever like going on walks even. Am I overreacting or could there be something wrong?