That's how proper risk taking should feel like. It should not feel like a gamble. It can fail but you should be confident that things will turn out well in the long run.
The key to this is to learn more. Learn about the environment. If you're investing in a business, learn the market, learn what they're doing, learn who the best player in that market is and what their unfair advantage is.
In fact, if you're investing, find the unfair advantage. Unfortunately, investing does involve a lot of research. The best stock investors I know will learn every company in the stock market by heart, pick out the best, and wait for the right moment.
Also don't be too worried about your looks. Josef Stalin was about your height, not very good looking, and he was able to intimidate soldiers bigger than him.