I've spent the last 10 years amending my sand, lol... Maybe if we mixed our gardens together, we'd have something... Every spring I turn over the soil at least a foot deep. Not to good for the worms, but seems to work well. My carrots grow 6 to 8 inches long now, and I get nice beets, where before I just got little nubby carrots and no beets.
well i just did a quick search and some say adding sand is a mistake....hmmmm....well it worked for me buTT i also added literally tons of compost over the years so maybe that is what did the trick....i added this winters chicken poop too....from the looks of the pics you have posted in the past it seems your soil is doing great anyway....i read where you planted bluberries....i hope you have better luck than i did....i spent a lot of money and time trying it here and eventually gave up