First plunge, too cold?

I was gifted a cold plunge pool for Christmas. Decided to try it out. The water temp was 50. I hopped in fast, laid out and could not get my breathing under control to the point I started hyperventilating about 20 seconds, and hopped out. Any advice or techniques? 34M 6’4, 210

Edit: I tried again and made a minute. Thanks for the advice y’all! My light research prior to jumping in did not have me mentally prepared for the discomfort and hyperventilation. But the deep breaths prior, hold, climb in, exhale, arms out, played some music, and told that inner bitch to go away 😂. Hit a minute. Tomorrow I’ll try 1:15.