Porsha Williams -- Kordell Stewart CHANGED THE LOCKS On Me!!!

Kordell Stewart REAALLLY doesn't wanna see his estranged wife Porsha Williams anymore ... 'cause the ex-NFL star just changed the locks on the family home to keep her out ... this according to Porsha.

The "Real Housewives of ATL" star just filed new docs in her divorce war with Kordell ... and it appears the nasty split just got even NASTIER.

According to the docs, filed in family court in Georgia and obtained by TMZ, Porsha claims Kordell has locked her out of their residence on multiple occasions ... and she had to have her lawyer beg Kordell's people for a key.

Sources close to the situation tell us Kordell isn't playing ball -- and hasn't forked over a key.

But there's more ... according to the docs, Porsha tried to work things out with Kordell in a mediation session, but she claims he blew the whole thing off ... and called it a "waste of everyone's time."

Porsha wants a judge to force Kordell to either allow her to use the house ... or pay her enough cash so she can get a "suitable alternative residence."

Sources tell us Porsha is currently living with her mom in ATL -- guess she feels it's just not a "suitable residence" for a grown woman.