General anxiety over birth

I'm currently 22 weeks 3 days tomorrow with my first successful pregnancy 💙I'm due June 24th I'm only 20 and 4 ft 11 and 7 stone I also have severe low blood pressure to were my hearing and sight goes and I nearly faint. I am wanting a natural birth as in no pain meds other than gas and air and paracetamol 😂I have a severe fear of labour I don't know why but I'm so worried that something is going to go wrong like my blood pressure drops crazy and I go into shock or something or I need a c section but something awful happens because of my low blood pressure I'm terrified was anyone else like this or anyone haslve similar fears but we're totally fine? Thankyou ❤️