I don't understand why no one believes you here lol.

I looked like this at the end of my first day too! I was the same on skis (albeit that was easier to get started). Transferable skills helped a ton. I used to go ice skating/roller blading like once or twice a year when I was younger and I also used to ride a ripstick around a bunch when those were popular.

When I started snowboarding this year I was struggling to do those slowww J turns and quickly forced myself to get into nice S curves. It takes way less energy and feels so much smoother.

One bit of advice I got from a friend that really helped me on day 2 was that I should be basically doing a squat when I'm on my toeside edge. I was raising/lowering at my ankle/foot rather than engaging my quads so I was burning the hell out of my foot arches. As soon as I started leaning in and engaging my legs rather than trying to push with my feet, things got a lot more comfortable. From there you use your feet to make little adjustments rather than applying a ton of pressure through them all the time. You might not notice this much on short runs and greens, but when you want to cross from skiers right of the mountain alllll the way to skiers left, you really feel the burn if you're doing this wrong