extremely soft 2nd to 3rd shift

This is just scaring me because its the only form of transportation i have the moment and getting that transmission shop to do anything is like pulling teeth out of a tiger. I really hope its something simple that i can fix on my own. But this just came out of no where, it was shifting thru all gears perfectly, not to firm but not to soft and no all a sudden the shift from 2nd to 3rd is extremely sloppy and soft.