Why do I?

Why do I always feel sad? Why do I always feel angry? Why do I feel like this. I'm scared of myself. What I can do. What I'm capable of doing. All I do is cry and pretend like it's normal. Try to bury my problems deeper and deeper, hoping they disappear. But what if it's act? How do I know what I'm actually feeling is true. And not just made up to make me feel better about myself. Or just an excuse to cover up or mask of how much of a terrible person, I actually am. Why do I act like this.