Hi Mat have you seen a doctor for this diagnosis? Bronchiitis can be serious if not treated correctly.
Are you coughing, feeling sick, got a temp, etc?
I drink ice water to soothe my throat, though hot drinks can help too. Lemon & honey Strepsils always help me.
Steaming the shower up and closing the door can help, as the water droplets in the air help soothe your throat.
Just rest and stay hydrated. Take the day off work if you can. Limit fatty foods or drinks, and eat a bland diet as spicy food, or jagged foods like nacho chips might aggravate your throat more.
Taking Paracetamol and Ibuprofen together can also help to bring down your temp if you have one, and to help with inflammation (always follow the instructions on the box/es of medication).
If the bronchitis gets worse, do go get antibiotics as bronchial infections cause a build up of mucous (phlegm) in the lungs, and if it's not coughed out (expectorated), it causes serious infection.
Hope you feel better soon!