700R4 Trouble

[Caleb]

My 700r4 was leaking so i thought id replace pan gasket to see if that would fix it. figured i would put my B&M shift kit in too if i was gonna pull the pan off. (no sense in doing it twice) so i followed directions went slowly and took my time. about 7 hours. heres where it starts to get trippy. it engaged in park, engaged in reverse, and now DRIVE wont engage till i drop column to lowest gear 1. when i get it in drive i can push the petal to the floorboard and barley get up my driveway. engine will rev through the roof almost like im still in neutral but i can slowly move. got up this morning and it magically works fine. still have to drop to 1 but it works fine. shifts all the way through OD. when i went to get gas a few hours later its back to not working how it was before?? what is going on. it cant be any valves or accumulator right? if it was it wouldnt have started working randomly? i got school and work i need help please.