disco 2 3.9v8a auto box problems

[danny 3.9v8a]

Hi i bought my first disco last march its a 1994 disco2 automatic 3.9v8a its lay unstarted from may when i done about 150 miles with caravan on tow .went started her yesterday took her hour drive on way home my gearbox collent red light came on and she wouldnt change gear stoped right away called friend who brought me fluid put it in light went out but total loss of power engines fine plenty life so drove her up couple hills she was screaming stuck in gear then she just stoped smoke coming from under neath let her cool tried again no gears but reverse kicks in eventually i must state th
is when away in may towing she didnt fell right i think i had her other box in high gear
i did use my 1 2 3 on auto box but she seamed slugish i was glad to get home can any one help whats wrong with her also no dif lock in park position help help

 

[Disco Mike]

First of all that a D1 not a D2.
Any fault codes, when was the last time it had a major service and how many miles on it?