If you feel you are not doing as well as you could, you'd say, "I'm really lagging behind". You could say, "I'm not pulling my weight"', or "I'm going to be the last one out of the gate". All these expressions mean you are not doing as well as others. If you think your reaction to your performance was too extreme, you could say, "I am making a mountain out of a molehill!". This means you are making a small problem seem bigger. You could also say, "I know I'm laying it on a little thick", if someone tells you you are overreacting. Hope this helps

You could make your own idiom or hyperbole. Or you could use a simile. I think idioms can be exaggerations in and of themselves. Hyperbole -I practically become a "drama queen" when I am studying English. You can say, as a simile for exaggeration: I drink English like the water of a man stranded in the desert. The closest I can think of is "Don't have a cow." which means don't overreact. However, you can adjust it to say... "I almost have a cow when I study my English!" Here is some info I found while surfing the net. :-) Hyperbole is an extreme exaggeration used to make a point. It is like the opposite of “understatement.” It is from a Greek word meaning “excess.” Hyperboles can be found in literature and oral communication. They would not be used in nonfiction works, like medical journals or research papers; but, they are perfect for fictional works, especially to add color to a character or humor to the story. Hyperboles are comparisons, like similes and metaphors, but are extravagant and even ridiculous. They are not meant to be taken literally. http://examples.yourdictionary.com/examples-of-hyperboles.html https://blog.udemy.com/idioms-and-their-meanings/