Transmission not working properly

Hi, I have the truck listed above all stock. I recently rebuilt the entire transmission 4r70w I did the rebuild. I finished put it back in the truck then I changed the starter flywheel also and rewired the battery cables to starter and engine block everything checks out perfect so far. Then I replaced the timing chain I made sure both dots line up with key on crank aka top dead center. Put all back together been siting for about 4 months without moving. I started her up today and she fired up very rough but she was idling great. I took my timing light and before the fire up she was at top top dead center 0 degrees perfectly on balancer. She's running i'm tryin to time her during trying to time her she started smoking. I thought oh its ok no biggie 4 months sitting burning off maybe water or something. Dirt spilt oil, didn't think anything of it, then it got worse. Started hearing almost metal screeching not too concerning but enough to be like; okay, turn off truck ASAP. So I'm at a lose no clue what's going on I have also tried giving it gas it wont go anywhere. Goes into gear perfectly goes into reverse boom instantly drive same thing instant, but when I push the pedal goes no where also to be more clear it goes into reverse then it will move very slowly but when I give it gas it wont go faster then I put it back in drive boom instantly goes into drive and moves forward very slowly but again give it gas goes no were at all period no power at all if you have any idea please help i'm desperate for help. So if this helps you here's what I have replaced and done in past 4 months of it sitting. Oh, and also I did unplug the thing on the timing case which I believe may be the crank shaft position sensor and plugged it back in that's all.

New fuel injectors cheapy ones not happy with them but $100.00 for all 8. I figured what the heck new timing chain.
New coolant, new oil, new intake gasket did not touch the valves at all or rockers no lashing nothing left everything alone. New battery, new starter new fly wheel, all brand new transmission parts clutches so on that's about it.