I have a 1998 chevrolet Tahoe and i think that my transmission is about to go out. My transmission is shifting hard from frist to second. The idol is jumping up and down and when i take my foot off the gas it fills like the emergency brake is on and it is slowing down. can you please tell me what is wrong with my truck.

Optional Information:
1998 Chevrolet tahoe 350

Already Tried:
check all of my fluids