Hi, and welcome; I'm sorry to hear about the troubles!

Your nitrAtes are a bit high (I'd do a 25% change and aim for 10), but ammonia and nitrIte at 0 are good.

Can you fill out these questions, as they'll help us get a better picture so we can help you more.

Do these white areas look like ulcers, or like there might be pus around them?

Any fuzzy material?

Can you check for velvet? The darting behaviour sounds like it may be what we call "flashing" -- it's the fish version of itching. Using a flashlight can help you check for velvet.

~Ash