Stressed out :( in I do exist

Our dog has fleas :( I am so stressed about it? Anyone got any advice for me? How much do you have to clean, wash....I have already had her treated at the vet this morning with a spot on medication. I am going nuts here! Scared they are everywhere and I won’t be able to get rid of them :( Any help? Do I Need to wash everything? The clothes we are wearing? His collar? His bed? The Sofa......HEEELP please