That's definitely a good idea, it seems like you don't really know why it's happening. A good psychologist should be able to get to the bottom of it. I hope it's free where you live as there are many bad psychologists that have no idea what they're talking about. I hope you don't have to deal with one. But, you could maybe check to see if they're any good by googling their names and reading the reviews, if there are any.
I used to have a problem with my emotions controlling me, but now I mostly always in control of them. I think it's when I started to become more cognizant of them that I was able to control them. That's not to say that I can instantly make myself happy or joyful, but when I notice that I'm feeling a negative emotion I can tone it down quite a bit and sometimes make it disappear completely.