John -- whose penis was notoriously hacked off by his then-wife Lorena while he was sleeping -- just had another gruesome amputation to his extremities.

JWB tells TMZ ... two toes on his right foot have now been amputated, and the first amputation triggered the second.

John explains he lost his big toe on his right foot last year after a callous formed, and an infection spread to the bone. He says that led to the next little piggy getting chopped off.

JWB tells us his second right toe was amputated last weekend at a hospital in Vegas. He says the toe was fractured because his previously amputated big toe left him with no support on the foot, and as he limped around, the pressure he was putting on the second toe caused it to shift and break.

Making matters worse ... his left foot was in a cast as doctors weighed amputation on that body part, which only added to the strain.

Remember, John says he suffers from neuropathy so he didn't know the toe was fractured until he went to a doctor for a checkup. He says the doc noticed the problems right away and recommended amputation.

John says he's been released from the hospital yet again and now he's got a bandage on his right foot and special shoes so he can walk. He tells us he also uses a knee scooter to get around.

JWB says he's on the mend and is finally feeling healthy ... but he's still got a lot of work to do and he's seeing a podiatrist.

He's been through so much. Still, the first cut is the deepest.