How wide is your board? A narrower <30 works much better in steeper waves.

Great fun learning

enuenu, I know exactly where you're coming from... it's a trap for experienced short board riders hoping onto a big SUP (as in over 10') and getting into heavy situations that are great for the short board but dangerous on the SUP (without a lot of SUP experience). By way of example, I've been a short-boarder for about 40 years and bought a 11'4 Nalu for riding the 1 footers in the river as my first ever SUP. I quickly learned that it was 10x more fun getting that big board out into the surf and I naturally gravitate towards the same waves that I would on the short-board, my favourite is a wedgy little reef break that I usually surf alone. The 11'4 supertanker isn't really suited to the wave, it just doesn't have the rocker or the agility to stay out of trouble on a real drainer. On the real bad wipeouts, it all happens in a blink of an eye and can get pretty nasty... My last session ended in a couple of broken ribs, chipped tooth and at least a few weeks recuperation.

As for getting through the beach break, my local beach has horrible shore dump which is pretty tricky... I just pick my time, get a good head of steam up and surf stance over the foam. If I get knocked off, I just paddle prone or paddle on my knees to get out of the immediate danger. In my case, there's always a deep gutter only 20m out from the dump, so a quick dash for clear water is usually successful.