Well it lasted yet another year and started overheating again. Seemed like it ran fine until it reached the point where it had to open the thermostat and found no relief so it just kept heating up. I removed the radiator and got it cleaned inside. The person told me it only had 2 lines where water would go through it. He believes that when I did the flushes it loosened and removed all that junk inside the engine and clogged up the radiator even more. I'm satisfied because now the tractor stays around 1/4 on the temp gauge and everyone is happy ! Can't wait to test it this summer in 104 degrees !!
UPDATE: After taking the radiator to get professionally cleaned, I've used it now for 2 summers, sometimes in almost 100 degree temps, and it's worked like a charm !! Almost paid thousands to repair my other tractor too, and it was just the same thing, clogged radiator fins and a hairline crack on the top of the radiator. Both are working great now !! I have to stop over-reacting and working myself up, and just call a mechanic first the next time. Thanks to everybody !