You have to be okay with wins and losses. You can't just be looking for the wins and, when the losses happen, you can't buy more and more because you're sure it's going to bounce. We call that revenge trading.
The nature of trading demands that you have an objective and logical approach. If you are experiencing extreme elation after a winning trade and likewise extreme disappointment after a losing trade, then you are riding an emotional roller coaster: Up and Down, Up and Down. Your account balance is probably doing the same thing jumping Up and then Down. Many go to the extreme of picturing and trying to become an emotionless being, such as the ultra-logical Mr. Spock from "Star Trek." That's fine just realize it is not easy. After all how can you not get at least a little excited after a win and become just a little disappointed after a loss, its human nature, it's natural to feel that way; and that's the point, it is not easy to control your emotions, it takes lots of practice, but it is possible to control your emotions in order to achieve your objective, a logical mindset that is conducive to profitable trading.
amount of money you risk on a trade (think position size for instance), you'll be able to tell yourself that the actual downside is bearable; you'll know you can easily survive the worst case scenario. It will also help a great deal if you have a detailed trading plan and keep a log of each trade with clearly spelled out strategies for how you entered and how you will exit.