strawberry huff

The "huff" is usually used by those who have just performed a difficult task, such as reading a long book or picking up a heavy object. It is very similar to a "sigh", but is more aggressive sounding. It can also be thought of as meaning "hard" or "tough"

"Strawberry", is used in a similar way that "really" or "very" is. So when placed before "huff" as in "strawberry huff", it means "very tough" or "really hard".