Tiffany Haddish is living a straight-and-narrow existence … saying she’s been off substances for well over two months — though admitting it’s not totally by choice.

The comedian joined “The Conversation with Amanda de Cadenet” Friday where she revealed she’s living the sober life these days … claiming she hasn’t drunk, smoked weed or done anything else in about 72 days.

TH says it hasn’t been super hard for her … ’cause she says she’s never been a big user of substances anyway — so she’s cool with giving all that up.

But, don’t get fooled … Haddish isn’t totally making that decision on her own — ’cause she claims she’s actually been ordered by a judge to lay off any and all substances.

Tiffany also adds she would’ve fought her most recent DUI charge if the stress wasn’t doing a number on her health — saying she was just driving while tired.

Of course, Haddish copped a plea deal in her Hollywood DUI case … pleading no contest in February to a conviction of reckless driving — a much lesser charge.

Remember … Tiffany was arrested in November when cops claimed they found her asleep in her car, parked awkwardly on the street. She was released pretty soon after, and joked about the incident during a comedy set pretty quickly after.

Through all the jokes, it seems Haddish has really made a huge change to her life — even if it wasn’t 100% her idea to begin with.