if you want to work in physics you will be required to go to grad school. without at least a masters' degree, your prospects will be severely limited. also, physics necessitates working in academia for most of your professional career. there are plenty of private sector jobs for a physics major but the vast majority of work you will have available comes from the government or agencies which do work for the government.

on the CS side, it depends on what you want to do with your degree. if you want to be a programmer, or go into some kind of development, then CS is perfect and you will get a lot out of your classes. if your CS aspirations do not involve programming or research, you will find that many of your classes have no relevance to the real world. this is ok as far as it goes, because having the degree will let you get your foot in the door at many places. but you'll have to make up the experience yourself somehow until you can find a place willing to hire you.

hope this all helps, good luck whatever you decide.