You do not understand how WTO tariffs work, Whatever tariffs we apply to the EU we must also apply to other countries that we do not have an FTA with.
A list of all of the tariffs the EU would apply to the UK is set out in the EU's Common Customs Tariff (CCT) schedule, for example lamb exporters to the EU would face a tariff of around 67%, whilst beef is around 85%.
Shame the stupid effing farmers in Wales who export most of their lamb didn't realise tha before they voted Brexit. And, before you say that is just more for us, your average British housewife would mistake a leg of lamb for a sex toy.
I am beyond caring now. I only hope that the f@ck-wit parts of the nation that voted to leave are the ones that hurt the most. F#ck them.