cradle cap and bathing questions.

Need some advice for a couple things. FTM here
1. My 3 month old has cradle cap 😞 and are there any good tips to get rid of it, and keep it gone? 
2. I feel really bad he screams bloody murder when bathed he has a bath seat (see photo), the water is warm (not hot) and it comes up to almost his little tummy. I sing to him but he still hates it. Any tips? I want him to enjoy bath time