I just saw you previously posted that you upgraded your rear shocks to the more expensive bilsteins for no good reason. You were even looking into OME struts...crazy. That money you could have saved with the 5100s could have been used for a rainy day such as today. My opinion is you need to get smart with your money.
With that said, your transmission is almost certainly done. Have you properly checked the fluid level? Here is the FSM:
https://www.nicoclub.com/infiniti-service-manuals