Master P: I'm Not What I Used to Be ... So Back Off Sonya

Master P is a shadow of his former self in the money department, so he wants his estranged wife to lower her expectations and he's asking the divorce judge for help.

The mogul sent a letter to the judge -- obtained by TMZ -- in which he says Sonya Miller is bleeding him dry with $10k a month in child support and more than $16k a month in spousal support.

He says her taste for the high life is insatiable ... he gave her $8k to find a new place to live and she wants another $20k to get a better crib. What's especially galling, he says, is that she needs a new place because she's alienated her landlord with loud parties and "rude and vulgar" conduct.

Master P says all he cares about is the welfare of his children, and he's distraught that Sonya just sits around and allegedly smokes pot with their 19-year-old daughter, who dropped out of high school.

P was frank in one of the documents, saying, "This is not the 90s, you guys don't know my situation."

It's interesting, Sonya's view is that she helped P build a $200 million empire, and now she wants a big piece of the pie.