My tranny takes toooo long to turn over to the next gear, I think that’* why I get terrible gas mileage. a little over 10 miles to the gallon when I check the trans fluid it'* still red which shows now sings of burning but it takes to long switch gears like hang up around 3000 to 3500 rpm'* to change to just 2nd gear and does the same for the other gears too, to where as when I’m accelerating up to about highway cruising speed my check engine light comes on and starts flashing because the gear takes to long to turn over to the next....can anybody help?

A flashing check engine light indicates a condition that could possibly damage the cat....generally misfires. Get the code pulled, even if the light is not on, there should be a stored code.