Spinach is OK. Sure, it’s not ideal from the purine perspective but on the other hand it’s the kind of food that helps your kidneys deal with uric acid. And if you take an adequate dose of allopurinol or similar, purines aren’t going to matter much while the helpful effect of spinach will remain relevant.
People who drink milk seem to have an easier time with gout than those who don’t.
Until you know what’s going on in your body and are taking effective medication, I think you ought to be careful with stuff like protein supplements.
If your supplement is plain whey without dodgy ingredients, it should be OK in moderation but excessive protein intake isn’t great for untreated gout or your kidneys.
Good luck finding a long term solution!