Yellowing and circles in the shower :0( help

[lifecamper]

Anyone have any good solutions to fix the yellowing of my RV shower? Also I used some suction hangers in the shower and they left almost brown circles. I've tried Fantastic and Kaboom but the stains remain. Was afraid to try abrasive. Any suggestions?

[spicercars]

We use the mr clean magic eraser it worked great for us.

[nano]

CLR did an amazing job getting rid of stains in the tub in our house.