Thanks for your question on Health Care Magic.
I can understand your concern.
Sertraline and
Nicotine patch can not cause
bad breath.
Bad breathing is mostly related to oral cavity problem like caries teeth, decayed teeth, gum bleeding, abscess, perotitis etc.
So better to
consult dentist and get done clinical examination of oral cavity.
Avoid garlic and onions from the food.
Wash your mouth thoroughly after meals.
Drink plenty of fluids orally.
Rinse your mouth with anti septic solution like
chlorhexidine.
Don't worry, you will be alright.
Consult dentist and discuss all these.
Hope I have solved your query.
Wish you good health. Thanks.