Emotions and feelings are often used interchangeably as if they are the same. Whereas in everyday language you may not differentiate between them, for your organism these are very different.
Emotions can be a result of your thoughts but also of your body, and they affect you first on a physiological level before you consciously realize you experience them.
Feelings, on the other hand, can be the result of an emotion. This is your conscious response to a specific emotion after you realize you have it.
Emotion first affects your body, causing different changes, such as:
After changes described above happen, you realize that you experience an emotion and start consciously evaluate it, which gives you a specific feeling.