ATF leaked on ground!!

[Dietoremain]

So i parked my truck in my driveway last night, came out this morning to find a good 3" puddle of ATF on the ground.. doesnt smell good, and its all over the back of the pan just before the crossmember.. i was driving normally. used my tc lockup and downshifted to 2nd to slow down 5 mins before.. but parked it and it was shifting fine the whole time.
Im supposed to leave for a week long trip in the morning. pulling my horse trailer 100+ miles there.
Fluid did smell possibly burnt. Looks like im spending my day packing and dropping my pan and doing a fluid flush and checking the magnet??