Transplant from ground to pot gone wrong! pls help!

two days ago i was given a 2 foot plant from a friends backyard, i was carefull to get the rootball as intack as possible, put it in a bucket filled with a potting mix, and put it in my grow room. it immediately showed signs of shock(drooping leaves/stem ect.), but it just got worse from there, most of the leaves have dried and fallen off and the stem is starting to dry too. all i could think to do was add a root stim and mist the plant every so often, but it doesnt look good. can someone pls help me!!

you've done pretty much all u can just water and keep moist. oh and say a quick prayer to jah

its just so sad looking... i almost feel bad for pulling such a beautiful plant out of the ground and it looking like this

you shouldve hydrod it i had same problem it was heat stress and i retransplanted it into good soil after putting it in hydro cuz my ac unit wouldnt work for 2 days and it almost snagged her she was kinda on her death bead ill say but anyway the soil kept her alive with a strong stem and i put her in today with the bubbleponic under 3 100W cfls and she is slowly regaing health