Skytrooper;
Hello and WELCOME!! You seem as though you've been around the gardening block once or twice, so I'll TRY to throw out only the points I think need be made. You only put down appx. one half pound of sulfur extra per 100 sq. ft. You have hard pan clay ( which is notoriously high in P.H.) and even though you didn't mention what kind of plants you put in, I'm betting that they are more high P.H. tolerable than they are lower. Try planting tomatoes, peppers or potatoes ( all nightshades ) radishes, rhubarb or sweet potatoes.Speaking for myself, I wouldn't put lime down, that's like throwing good money after bad.
Keep in mind that each season is ALWAYS different from the last, so your problem may not be from any amendments you add or don't add. I don't know anyone who marks things like precip. levels, wind speed/direction, ambient air temp.and so on every single day of each growing season, just for next years harvest!
My advice is to enjoy the low P.H. because sooner than you realize it'll be back up. I don't know where or what zone you live in but I'm sure adding a S$#T ton of compost wouldn't hurt either!
Good Luck & Good Gardening!
