Marc Anthony's Ex -- JLo Gets Child Support, I Get a Crappy Valley Apartment!

Marc Anthony's ex-wife claims the singer has turned a cold shoulder on her children ... forcing them to sell their home and move into a hovel in the Valley ... while he lives like a king -- and to add insult to injury, he pays the very rich Jennifer Lopez a ton of child support ... this according to court documents obtained by TMZ.

Dayanara Torres -- the 1993 Miss Universe -- wants a huge increase in child support -- from $13K per month for their 2 sons, to $113K a month. It's an enormous increase, but she says it's a drop in the bucket for Marc -- who this year boasted he makes $1.25 mil a month -- MINIMUM.

It's especially infuriating for Dayanara, who claims Marc played the poverty card during their divorce, claiming he had such money trouble he had to sell his private island and let some of his staff go. Now get this ... the week the divorce became final, she says he bought JLo a $4 MILLION RING!

Dayanara says Marc goes weeks and even months without seeing their boys, one of whom has special needs. She mentions one instance where he told the boys he couldn't visit because of work, but then they saw him on TV cavorting on a beach with JLo. They were devastated.

Dayanara gives Marc backhanded credit for giving the kids lavish gifts. For example, last XMAS he sent them 4 huge boxes of toys, including an extravagant Lego set. But she says their apartment is so small they have no space to play with them.