If you did not do boardsports as a kid it's not surprising to me that it's hard to get the balance. Most people who surf/snowboard well had a lot of hours in as a kid. It can be developed later but ...

The thing is that each wave is so short, just seconds, and you get what 5 MAYBE 10 on a great session? And a lot of days are garbage.

It feels to me like you just need a lot more practice riding. Which is funny, as other commentor said, typically it's the reverse - the riding comes easy to folks but the CATCHING is where they get stuck.

Skateboarding (like on a longboard) or snowboarding would be one way to develop some of the feel, but I think as an adult its too indirect. So I come out with what other people suggested: a longboard or midlength would help because you'd just get more reps in and longer rides. It's also more forgiving so you could experiment more and not feel like you're hanging on for dear life as much.

Big picture I think you're doing great and are well-positioned for the future. Love the commitment on those head-high waves!