You likely have a broken forward apply band. If you search for that in the trans section you will find a handful of other guys that have ran into this and that the symptoms are the same. The car will shift fine after it gets into 2nd gear from 2-3-4 and 4-3-2, but as soon as it goes down into 1st gear and the shifter is not in manual 1 range you will not have any forward movement. This means an overhaul as the forward apply band is one of the last things to come out of the case. If you drop the lower pan you may find a piece of broken band laying in the pan or you can look up at a windowed out section just to the right of the end of the filter and you will see where the apply pin applies the forward band and it may be broken or fractured and the piece has not fallen out yet.
