You've had a LOT of rain in TN this year and cherries do not like wet feet. They also don't care much for the acid soil you also have, which the rain made much worse. If you want this tree to live, you have to get it out of that acid TN dirt and into some decent soil that isn't as acid and drains much better than TN clay.
Start by purchasing some dirt. Look on craiglist. It usually sells for about $30 a truck load. Pile the new dirt on top of the TN dirt, making a raised bed. You could probably add some lime as well ($3.50 from lowes for 40 lb bag). Mix the lime with the soil real good and plant your tree in that. The raised bed will allow for good drainage and root aeration while the lime will add calcium for a healthy tree, as well as stopping the effects of acid soil.
I wouldn't put the tree in full full sun, it only needs about 6hrs of direct sun per day. Cherry is a small tree and would spend its life under the canopy of bigger trees naturally. It does need some sun to develop sweet fruit. I'd aim for 6hrs or so of sun.
Keep the area under the tree mulched with some fall leaves and maybe throw some grass clippings under as well.
The fungicides and pesticides aren't helping. You shouldn't need those with a healthy tree. The miracle-gro is fine, but it doesn't contain calcium and calcium is the #1 thing you need living in TN and growing things like cherries, pears, apples, grapes, tomatoes. The exception to that would be blueberries and blackberries, which happen to like native TN dirt.