The interview -- set to air on Monday -- was taped several months ago ... and a new promo for the episode features a seemingly confused Dina acting bizarre .. and many people suspect she was blitzed.

In fact, the promo features a clip in which Dina's ex-hubby Michael Lohan asks Phil if Dina had been drinking before the interview.

But Dina is adamant she was sober ... telling TMZ, "I don't care what it looks like. I'm fine and I don't care what anyone says."

She continues, "All people saw was two minutes edited of an hour long interview. Of course they cut it to make it interesting. That's their job . I don't blame them for doing that. Some of the comments were taken out of context but I'm fine. I'm fine."

Dina tells us the public shouldn't judge her until they see the full interview -- insisting she's a "good mom" who's always been there for her 4 kids, including her oldest daughter Lindsay Lohan.