Jan
Flying by the "seat of your pants" in IMC should not be attempted. "Feel" as with all the natural senses is unreliable and deceptive. Students of instrument flying will have such ideas removed very early on in the training.
Go back to the basics; Power + Attitude = performance and therefore it must follow Attitude + Performance = Power and to conclude Power + Performance = Attitude. So, if you lose the ASI then the job is to set the normal RPM required plus the correct attitude and the speed will be correct.
Know well the characteristics and the performance of your aeroplane especially on the approach. If the response to the control inputs is sloppy and the aeroplane is slow to respond then you are too slow. .