2001 Honda Odyssey transmission

2001 Honda Odyssey when I drive it like for 15
minutes the transmission heats up and right above
the transmission there's a little hose it. it starts
leaking oil really bad I don't know if it's a return line
for the transmission when the transmission gets
hot of maybe or is it connected to somewhere.  it
starts feeling like it's heavy that it loses power the
oil seems like it's thin and burnt  and stinky.  I want
to know if there's a solution  for it
instead of buying a new one. or I have to buy a new
transmission can I add like a  heavier oil that way I
don't have to change transmission. If someone can
help me please God bless you...