I was a psychology major for my first year of college before I switched to history.
Competition to get into graduate school for psychology is among the fiercest of all degrees. Basically, you have to eat, breathe, and sleep psychology to even have a prayer of a chance to get into a graduate program for psychology. Actual jobs are even more competitive, but once you are in the field for a while, the pay is pretty sweet. You also have the benefit of knowing that you are doing a world of good for people in need.
HOWEVER, you have to be aware that you will not be able to help everyone that comes to you. Some people are simply beyond help. Also, hearing people talk about their problems every single day can be incredibly emotionally taxing on you and you really have to have the patience of a saint to handle it.
I don’t mean to discourage you. If you think you have what it takes (extreme patience, research skills, writing skills, etc.) then go for it, by all means. It could potentially be very rewarding both emotionally/morally and financially.