He also says Amber attacked him after a birthday party went sour. He showed up late -- due to an important meeting he was in where he learned he'd lost a substantial sum of money -- and when everyone left, he claims Amber insulted him repeatedly in their room. When she failed to get a rise out of him, he claims, she started wailing on him ... and left thereafter.

Finally, Depp addressed the poop incident. After the birthday dinner, he wasn't home for a while -- but was soon informed that some fecal matter had been found in his bed, which he believed was human. He says he found it "so outside, so bizarre and so grotesque that I could only laugh." Later, he says Amber blamed it on their dogs, but Johnny noted their animals were tiny, and couldn't produce what had been left behind.

10:09 AM PT -- Johnny Depp just got into the gory details about his fingertip getting cut off during his marriage to Amber Heard -- which he says was the last straw for him to end it.

JD says they were in the middle of yet another fight down in Australia -- and out of exacerbation and frustration, he went to their bar to pour himself a drink ... this after months of being sober. He says Amber went on the attack, not just with insults ... but with a bottle of vodka, which he claims she hurled at him and which made contact with his hand.

Johnny says it was then that he realized he was missing his fingertip and that he was profusely bleeding -- and at that point, he says he had a nervous breakdown of sorts and went into shock ... which led to him writing on the walls in his blood, a culmination and expression of everything he was processing and feeling in the moment regarding Amber.

He goes on to say he was eventually taken to the ER, where he says he lied about what had happened -- telling them he'd gotten his finger jammed in a door, wanting to protect Amber. Eventually, though, he says he told her personal doctor the truth ... and after some time, got it fixed with surgery. It wasn't long after that Johnny says he ended the relationship.

8:50 AM PT -- Depp is making more claims about Amber, including the allegation that she would drink excessively and do illicit drugs around him -- even during periods when he says he was trying to get sober.

JD claims Amber could (and would) knock back 2 bottles of wine a night, no problem -- and not just that, but alleges he'd seen her take MDMA, mushrooms and "high velocity" speed throughout their relationship. Johnny also claims she refused to attempt to go clean with him.

One other thing ... Johnny once again described instances in which he claims Amber would pick fights over little things -- which he says would often blow up beyond his control.