[anonymous]

In my opinion, his behavior is not related to his diet. Many dogs suffer from anxiety, thunderstorm phobia and separation anxiety. Often there is a genetic component that determines which dogs would be more vulnerable. There are effective medications (prescribed by your vet) to treat this.
I would make an appointment with your vet to have him examined and to discuss medication options. Some dogs only need the meds for a few months or prn (as needed) in conjunction with other treatments, for example “The Thundershirt”.
Don’t be fooled by over the counter meds and supplements (waste of money).
Your dog is becoming aggressive during these episodes, youcould try putting a blanket over him, like a tent, a safe dark place. Refrain from getting “in his face” when he is upset.
Regarding food, I have heard good things about Pro Plan Focus Salmon for sensitive stomachs.

Excerpt below from https://www.vetary.com/dog/condition/thunderstorm-phobia
Diagnosis of Thunderstorm Phobia in Dogs
As this is a situational issue, your veterinarian will rely heavily on history and your observations of your dogs’ behavior during storms for a diagnosis (unless your appointment just happens to coincide with a thunderstorm). They can do some in-office tests to check the dogs’ fear response to noises and other unusual stimuli. Your veterinarian will also likely do a quick physical exam to ensure the dog has not harmed itself or experienced any physiological complications from the intense fear reaction.
Treatment of Thunderstorm Phobia in Dogs
Dogs should begin treatment as soon as this problem is recognized, as it will only get worse as they age. Your veterinarian can recommend a course of behavior modification and desensitization to lessen your dog’s anxiety during thunderstorms. Playing the sound of storms at a quiet level while giving the dog treats has been known to work in some cases. As the dog remains relaxed and has a pleasant association, the volume can be increased, and treats continued until they are no longer fearful of loud noises.
Your veterinarian may determine that your dog could benefit from anti-anxiety medications or a sedative to be used when a thunderstorm is eminent. Some owners have also had success with dog “wraps” that can comfort the dog by giving them a sense of being swaddled in a protective way. These products are available through many retail outlets and can even have the bonus of offering your dog protection from a static buildup in their fur.

This is not veterinary advice; consult your veterinarian.