There is no reason why you can't have a protein shake before & after! My husband does that. Just don't drink it immediately before or it will be sloshing in your stomach and you will be burping. The other thing is a meal replacement or protein bar. Some of those offer more nutrients than shakes.
It also depends on what your goals are. If gaining muscle mass is important, then high protein with complex carbs is important. But if you are just trying to tone up/decrease fat, then stick to protein only so your body will use your stored fats to burn for energy.