I made several changes to your model to get it to start converging.
Added a remote displacement to set the X Displacement to 0 leaving others Free because that DOF was unrestrained.
Changed the contact to have a 0.1 Factor of Normal Stiffness and added Adjust to Touch since the top rod was not touching the stent.
Changed the Analysis Setting to have 100 Initial Substeps and requested N-R Force Residual Plots and Distored Elements groups.
Changed the Mesh to set the Element Order to Linear and suppressed the fine mesh on the top rod. This lets the solver run much faster.
I stopped it after a few converged substeps. I don’t know if it will get to the end of your load sequence, but at least it has started.