1. Enough! You've talked too much!
>> Chega! Você falou demais! [exagerou e revelou um segredo].
2. You've talked enough!
You've said enough!
>> Já disse tudo!
>> Falou o suficiente!
3. You've babbled enough!
>> Já falou o suficiente! [no sentido de enrolar alguém].
4. I've heard enough!
>> Já ouvi o bastante!
Just for curiosity, take a look on the verbs which are related of talking continuously and too much:
To chunter (BrE) [informal]
Meaning: to talk for a long time about something that other people do not find interesting.
To keep on [informal]
Meaning: to continue talking about something in a way that sometimes annoys people.
To go on
Meaning: to talk so much that people become bored or annoyed
To hold forth
Meaning: to talk for a long time about something that is important to you, often in a way that other people think is boring.
Meaning: to talk continuously in a fast informal way, usually about unimportant subjects.
To drone on
Meaning; to talk about something for a long time in a very boring way.
Meaning: to talk for a long time about things that are not interesting or important.
To discourse on / upon
Meaning: to talk for a long time about a particular subject.
To ramble on
Meaning: to talk or write about something for a long time in a way that is boring, annoying, or confusing.
To be /go on about
Meaning; to keep talking about someone or something, especially when other people think it is boring.