I'm sorry to hear about the mussels. It's generally not recommended to consume mussels that have died before cooking, as they can spoil quickly and may pose a risk to your health. When mussels die, their shells may open, which is a sign that they are no longer safe to eat. Additionally, bacteria can multiply rapidly in dead shellfish, leading to foodborne illnesses.
To ensure your safety, it's best to discard the mussels that have died and cannot be consumed. It's important to handle seafood, particularly shellfish, with care and ensure that it is fresh and alive before cooking. If you have any doubts about the freshness or safety of seafood, it's always better to err on the side of caution and avoid consuming it.