Microstrip with coaxial cable in CST- too long calculations

Hi,
I would like to simulate a microstrip in CST.

On one side of microstrip there is coaxial cable, it's cooper core will touch the line. In the end of the coaxial cable will be lumped port between core and the end of cable (shield with pec). On the second side of microstrip will be also lumped port. Which solver shall I use: time or frequency? How should I set parameters for solvers that calculations would be quite fast, I am trying to solve it now, but it tooks more than 6h to solve it, and reasults are not physically possible (s11>0db in some parts).