need trans help! completely lost on this one.

Sounds like you are losing pressure,but if you had some trash in the pan your filter maybe clogging up after 10 minutes of driving and starving the pump.Changing the filter and fluid may fix it,at least when you have the pan off you can look for the magnet on the pan and see how much metal is attached to it....And if the filter looks clogged...
TXDart
P.S. Your car probably did not come with a magnet but if some rebuilt in the past it may have one.
http://www.slantsix.org/forum/viewtopic.php?t=34510&sid=7f4a1ba8f66c85f0cfe73546a41a23cb