I'm very similar. For the most part I've shut down many of the emotions because when I feel them I get overwhelmed. Typically when there is an expectation for me to have an emotion, like when all eyes are on me, I completely shutdown and try not to react.
As for happiness, and sadness, I consider these relative terms. For the most part I'm happy. Not much can get me down because I've seen the bottom, I know what it's like, and really most things that make people sad aren't that bad. Everything is relative to your own experiences as far as your feelings go.
What makes me happy is setting goals and accomplishing them. The sense of accomplishment and pride is unmatched. Especially when the task is challenging.
Also, I LOVE making a one-on-one connection with someone else. These are so rare in today's world and I find true joy in listening to someone open up and opening up myself. This isn't for everyone, but for me it really means A LOT.
I do have an issue expressing my emotions to others though. I would love to let someone know how much I love them, or enjoy their company. However, when the time comes the words get lost in a rush of thoughts and doubts and never reach my mouth.