HELP!!! I think i killed my baby!

So i just transplanted a 3-week-old plant from a dixie cup into a large pot. Problem is, when I removed it from the dixie cup, some of its roots (about 2 or 3 4'' long ones) ripped and the soil fell away from the root ball. Did I kill my plant? It is still standing upright in the flower pot but Im scared I may have just murdered it.

It should kick back and grow.

Also to add: I put it into fresh soil which I then watered thoroughly. I know I did not overwater because today is water day anyway.

it will be fine, i got a clone from a friend from an outdoor grow in a bucket, and there were like 5-6 bag seeds growing in it also, plucked them out and put em under some lights and they are the strongest of the group

yeah if anything you may just suffer a little slow growth while it rebuilds it's roots, but so long as you packed it into the new soil properly and it continues to recieve proper water and light I think you'll be okay.
Next time loosen the soil by tapping the sides of the cup then lay it sideways on the new medium right next to the hole, and slide the cup off the soil instead of dumping the plant out... then you can just kind of encourage it into the new hole you've made in the new pot.
That's the best way to go about it, if you can. Many people will loosen then turn the whole thing upside down and tap the plant out... but that can often lead to problems like you had.