Why do I feel my emotions so strong?

I am 23 male. When I am happy, you can never take a smile off my face; when I am sad, I become really depressed which sometimes leads to an anxiety attack; and when I am angry I feel a lot of rage. A lot of the time I am in a good mood, I am patient, but when I am sad I get so depressed I do not want to talk to anyone and become moody. Lately I have noticed I have been on edge because of work and taking summer classes for college. I also tend to bottle my emotions. I do workout and am a very healthy eater.