[ Other - General Health Care ] Open Question : I Always Feel Like I'm Going To Pass Out?

Your Question I Always Feel Like I'm Going To Pass Out? Okay, so i'm 15 years old, not underweight, not overweight, and 5ft6. I've always been healthy, but for the past few months now, I always feel like i'm going to pass out. If i get up from sitting or lying down, not even getting up that fast either, I have to spend about 1 minute trying to get out from a dizzy spell, as soon as I stand up the whole room spins, my vision blurs and I have a massive hot flush and have to hold onto something. Also, sometimes when i'm just out and about I feel like i'm going to faint, I get really hot all of a sudden, my heart starts racing, and i can never see properly. The other night I was camping with my friends, we hadn't been drinking but i'd just popped into my tent, when i got inside i had another of my attacks where I can't see or breathe properly, but this time I couldn't yell for help or anything, because I couldn't move, a few minutes later my friend came in to see what i was doing and I wasn't responding so she dragged me out, and i couldn't breathe properly, but for the rest of the night I was fine? this always happens to me but i never actually collapse, i'm too scared to tell my parents, but i'm so scared of it happening to me when i'm alonee, helpp?!