interesting issue at hand

so i bought this 96 lumina a year or so ago and it had a engine and trans swap from an 02 gtp. it ran great until today. i've searched this forum and found a few things but would like to clarify a bit before i start spending money.
i'm pretty sure its the forward apply band from what i've been reading.
came to a stop sign and suddenly didn't go anywhere. reverse, 1st and 2nd work ok. drive and od don't do sh!t. well, it seams like it wants to, sort of like a really bad slip minus any noises. it just slowly rolls. so that alone made me think its the forward apply band. but i started talking with a buddy and he said to unplug the harness on the top of the trans and i should be able to limp it home. sure as **** it worked. in the OD position too, just didn't reach OD on the way home. but it seams like its starting off in a higher gear or something.. sorta hard to explain.
i don't have the money to go take it in so don't even mention it. i just got done with automotive school at Lincoln Tech and am very confident in doing a rebuild. its just the lack of experience and diagnostic skills that are whoopin my a$$.

all i'm asking is for clarification.. to see if i'm right or maybe i got it all wrong. thanks in advance

Sounds like forward band to me.

Maybe by unplugging it, it starts itself in 2nd gear?

But I'm unsure.

that's what i'm thinkin.. but i also heard there's a chance its the transmission control solenoid.

i've read some more that when i disconnected the harness it puts it in limp mode (2nd).. which makes sense.. the slow starts and all.. but it did feel like it shifted. should have paid more attention to that. but cruising down the highway on the way home i was doing 65mph at about 25-2600rpm and normally that speed is around 1800rpm. not sure what gear that would be. just trying to throw more info out there on whats going on.

did some further testing.. got the harness connected back up. went for a spin down the road to log what it does.
from a stop:
OD- nothin
D- nothin
2- go
1- go
i can manually upshift all the way into D from 1st. OD will even keep me going but wouldn't shift to it as i was too low of speed.