To make matters worse

To make matters worse is an idiom that means to make an already bad or difficult situation even more so. It is used to comment, sometimes humorously, on how things are changing for the worse. It is usually followed by a description of what is making the situation worse. For example, "I was late for work, and to make matters worse, I forgot my wallet at home."

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add insult to injury
Meaning to make a bad situation worse to further hurt the feelings of someone who has already been hurt to worsen an unfavorable or uncomfortable situation ...
Example Sentences The company rejected his application for a job, and to add insult to injury, refused to pay his expenses. ...
Origin The phrase is an ancient one, but was recorded in English in the mid 1700s.

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when it rains, it pours
idiom
US, informal
—used to say that when something bad happens other bad things usually happen at the same time
The team not only lost the game but three of its best players were injured. When it rains, it pours.