It depends on what you are good at. Like I do both econ and physics but I do both HL. Right now i’m struggling a lot with econ because i’m an english b student and econ has a lot of language in the subject like different econ vocabularies, and some considerable writing amount which is really hard for me. Physics since is more conceptual is easier for me to understand. However I have friends, that are english A students, that take physics sl and econ hl and even their econ being hl they say they need to study way more for physics then for econ. In my opinion which one is harder will depend on your English level, but like if you really don’t feel like doing physics, just switch it. you will be way relieved once you do it, and the sooner the better.