Codes P0101, P0123, P2135, P2101, P0112 and P0223

Hello, I need some advice for an issue I have been dealing with for the past year with the car. The original problem that I had was engine stalling, hard starts and my car would randomly go into overdrive while driving on the road. I got it scanned and the code P0101 was retrieved. I replaced the MAF sensor with Hitachi brand however the light came back on I thought maybe I purchased a faulty one so I went and got it replaced with a new Hitachi MAF sensor but the light still came on after a few hours. I then replaced the Hitachi MAF sensor with an orginal Nissan MAF and the same problem persisted. I then took my car to the dealership where they updated my ECM, did a throttle body cleaning/ relearn and changed my spark plugs and coils. The next morning my check engine light came back on and I took it back to the dealership. The mechanic suggested that it could be the throttle body and that I would need to replace it however they were charging $800.00 just for the part alone and I had just paid the dealership $900.00. I drove the car for a little and the same issues persisted, making my car very unreliable because some days it wouldn't start. Many times, my car would stall, and I would have to press the gas enable for the engine to stay on. I took my car to different mechanics, and I have been led in circles. One day after work, I got into my car and started my engine however the car would not move after switching the gear to drive. It just made a loud noise from the exhaust when I pressed the gas. I eventually got the car started and I went directly to a mechanic. He insisted it was the throttle body and sent me a link to purchase a original Nissan throttle body part online that was cheaper. I purchased the part and he installed it and reprogramed the throttle body and cleared the codes. However, on my way home the check engine light came back on and he referred me to an electrical auto shop suggesting that it may have something to do with the wiring. After taking my car to the shop and paying for a diagnostic they suggested that there was a clog in my catalytic converter and that it would cost $950.00 to replace. They said there were no electrical issues or vacuum leaks in the system. I went to a muffler shop in hopes of finding a catalytic converter and they didn't think it was the catalytic converter along with the other mechanics based on how my car was running. There was no code, no smell, and the air coming out of the exhaust wasn't unusual. I bought a scanner to try and get the codes and do some research before spending that kind of money. The codes that were coming up on the car is P0123, P2135 (permanent), P2101(permanent), P0112, P0223, and P0101(permanent). After doing some research these codes have something to do with the Throttle Body. The TP% at idle is averaged at 2.7 and it does go up and down for a second. I dont know much about cars but hopefully this information is helpful. I am wondering if I purchased a faulty one online and I don't think I was getting these codes originally with my old throttle body. However, the auto shop I went to after replacing my throttle body didn't highlight the throttle body as the issue. I am not sure what to do or if anyone has any similar issues. I just don't want to keep putting money into fixing the car and the issue is not actually being fixed. Any suggestions would be greatly appreciated.