Extreme nerves playing blitz

After deciding to get back in to chess, I started watching a few streamers - and found them to be very informative. I had heard of blitz chess before, but ever played it. Of course all of the streamers can play, commentate and make a cup of tea (hot drink of choice) while making three minutes seem like hours and hours.

Well....as a returnee to chess, and seeing a healthy community online, I thought I'd have a go: failed.

But no matter I thought, it is just a lack of experience. I wanted to practice tactics, do some study, get my eye in again, so to speak and then give it another go.

Well, I have done just that - easing myself in by playing anonymously on 'the other chess website'; and I have found that  I get seriously stressed - I mean literally shaking; I am playing anonymously, so I am not concerned about ratings, but I just seem to have a weird reaction. I know blitz isn't a good way to improve, but I would like to have fun with it.

Have anyone else had this? Is there a way to fix it?

(P.S. I am not a naturally nervous person, I have played guitar in front of large audiences with no stage fright, and in my current job I guest lecture occasionally, I have no trouble speaking in front of 200 people.)