By changing your sentence order :

Je ne mange aucune viande sauf des produits de la mer.

I don’t eat any meat but seafood.

and adding adverb :

Je ne mange aucune autre viande, seulement des produits de la mer.

I don’t eat any other meat, only seafood.

By accentuating while saying it :

Parent: Pourquoi n’as-tu pas sorti les poubelles ?
Enfant: Mais J’AI sorti les poubelles !!!

In french, (like in English imho) repeating is already emphasis.

There are two issues that can lead to misunderstanding when translating your sentence. In modern French viande is used to describe any meat that is not seafood. Moreover seafood doesn’t translate to fruits de mer because the latter doesn’t include fish, only shellfish.

You might thus say:

Je ne mange pas de viande, seulement du poisson et des fruits de mer.

If you want to keep the English sentence structure, you might say:

Je mange bien des fruits de mer et du poisson, mais aucune autre protéine d’origine animale.

but that might surprise the person you talk to for being quite technical.

About your dialog:

Parent: – Pourquoi n’as-tu pas sorti les poubelles ?
Enfant: – Mais si ! Je les ai sorties !!!

The emphasis in French is put on the contradiction of the previous statement.

For this you can use “mais… “, “c’est faux, … “,” en revanche”, “cela dit” with the adequate voice tone. Some interjection can also be used: “eh! J’ai sorti les poubelles !” Other emphasis word (“bien”, “volontiers”, “déjà”) can be used to highlight the opposition of statements like:

Je ne mange pas de viande, cependant je mange volontiers des fruits de mer.

J’ai déjà sorti les poubelles!