2002 dodge caravan sport transmission?

[kelleyandjohn2000]

i have a 2002 dodge caravan sport 3.3l.earlier tonight we started out and it was like van didn't want to go seemed very sluggish,we checked transmission fluid and it was low.we added some and it seemed to drive so much better and smoother.several hours later i decided to go somewhere else and its like when i would stop at a stop sign and i would start off it seemed to shudder then would go but seemed to strain.also when letting off brake van seemed to come to a stop on its own like i was slowly pressing brake.any suggestions???thanks i really appreciate it.