You keep insisting on this approach of repeatedly designing without doing this check by yourself. A simple and well-known metric to know whether the system will be stable or not is to verify that in phase -180 if the gain is greater than 0dB. It was at this point where we expected the cursor to be positioned. By the way, adding poles will not stabilize your system, as opposed to adding zeros as well. A good way to do this would be to use the Lead compensator, which by having a zero dominant to the pole, would be pulling the phase up, thus giving a larger working margin for the gain.