Transmission will not go on reverse only first gear, codes P0891, P1775, P0731, P0732, P0841and P0846

My vehicle started shifting problem by not shifting into 3rd and 4th gear but 1st, 2nd and reverse gear. Then I diagnosed it using Bluedriver scan tool and It recorded P0891(transmission relay always on), P0841(low/Reverse pressure switch rationality), P0731(gear 1 error ratio), P1775 (Torque converter clutch latched in Lu position), P0846(2-4 pressure switch rationality), P0732 (gear 2 error ratio). Then I used the factory diagram from all data to trace and noticed that low/Reverse pressure switch circuit and 2-4 pressure switch circuit melted together at the pressure switch/solenoid pack assembly connector. I separated the two circuit and P0891, P0846 and P0732 gone and the vehicle began to shift into 3rd and 4th gear. Later I noticed that the vehicle was too sluggish on 1st gear and hardly climb bump and little hilly slope. Then I diagnosed again and recorded P0841, P1775 and P0731. I decided to change the solenoid pack/pressure switch assembly and replaced it with used one and the vehicle stopped going reverse, 2nd, 3rd and 4th gear. Above all it retrieve back P0846 and P0732 and deleted P1775, P0841 and P0731. I have changed 3 different pressure switch/solenoid pack but it was still doing the same, I interchanged the low/reverse circuit from its original terminal 2 to terminal 1 and 2-4 pressure switch circuit from 1 to terminal 2 to see whether the basis of the fault code will change from P0846 to p0841 and its still showing P0846 and P0732. At this point I don't know whether its the PCM or the transmission itself is now the problem. I have done all the troubleshooting step according to fault code description on all data but still I am not getting what I wanted, please anyone with direct solution please tell me, let me solve this and started using my vehicle.