Do you have a 2nd person to watch what is going on? Have someone push the kickdown linkage back and forth and see what is happening down below. Is it binding on something? After you "tweaked" it, now you can't push on the accelerator. Sounds like it got worse when you adjusted the rod. Almost sounds like the kickdown is not attached at the right place. Do you have a photo where the kickdown is attached to the transmission? The kickdown lever hitting the shift lever at transmission?
While car is on ramps or stands, put trans in 1st gear, move kickdown lever back and forth and see what is happening below. Use wheel chocks. Quick article about kickdown and different length levers.

https://www.hotrod.com/articles/the-lowdown-on-stock-torqueflite-kick-down-linkage/