windara said..
just hang in there and get out there as much as you can. It gets better :)
Yep. I was close to 90kg when i first got my 10'6.5'' -- it can handle your weight, I'm sure. You will make progress every time and get comfortable pretty quickly. You chose a great board.
A tip: Keep the paddle in the water and use it for balance between waves (almost like gently stirring the water - it's a 'feel' thing). And sometimes just keeping moving helps -- and gives you momentum if you are moving when the wave arrives.
Windara is right... stick with it. If you went and bought a bigger SUP you may well be wanting a smaller one in 6 months. Besides - the Nalu is a great all rounder. I love mine in the surf and now find it super stable. That said, I still go down for no reason (a little side chop when my weight is in the wrong place) sometimes -- my mate calls it "the sniper in the sandunes."
Enjoy the journey.

