Unknown Problem

please help last night everything started off being fine. i went and got gas when i left the gas station everything seemed normal until my turck tried to shift into second. i have a 95 chevy s10 2wd 4.3 liter vortec and when it wnet to go shift into second it kinda seemed like it shifted into second and the rear brakes seized up but the breaks are fine and something is def worng i put it on jack stands and when i put it in drive it will not shift through any gears it will act like it wants to go into second but it wont and then when i let off it will but it acts liek the 2nd gear is like a break it slows the tires way down and then shifts back into first.