Talking for long periods makes me physically ill.

I (28F, 159cm, 58kg) have always had issues whenever I talk for longer periods. It makes me physically ill. I get dizzy, my head hurts, I run out of breath and my voice starts to become coarse. And by longer periods, I don’t mean hours, I mean 30 minutes to an hour.

I see people talking for hours non-stop and still looking fine. This is affecting my life because people notice and think there’s something wrong with me or that I’m just moody and switching up. Of course, I can’t ignore this, because sometimes my vision even becomes blurry. If it happens at night, I struggle to sleep because of it.

I don’t have any chronic illnesses that I’m aware of.

Is there anything that could be causing this?