Any psychologists here?

I'm just wondering if there's anyone here who could explain my estranged state of mind. When i feel angry, is this self inflicted? In other words am i just angry at myself? On the other hand sometimes i feel involuntary feelings of love (for everything) peacefullness and appreciation (much like being stoned), but only for a short while then i'm left with an empty feeling. Why does this good feeling go away? How did it get there?

Basically i don't feel like i'm in control of my feelings. Is it possible to be in control? I don't beleive i have a problem i'd just like an insight into how the mind works!