Regarding SICP. The first chapter is too mathematical. At least at first glance. Is that true? When did you do SICP? How mathematically mature were you?
Highschool math is all that is required for it from what I remember, definitely doesn't require a lot of mathematical maturity. Even if you would somewhat struggle to completely understand the math, the ideas they try to teach you should still be accessible in my opinion.
I agree with you. They assume the level of math of an MIT freshman. And the level of computer experience of a modern 11 year old. So sometimes they lean on the math in situations where a professor today might explain something in terms of a computer. Take a step back and try to understand the concepts that they are explaining, even if your math is a little rusty. I love SICP, it really make functional programming click for me. The other book I recommend in this space is Advanced R.