i was a compulsive liar all through my teens and early 20’s.
i managed to stop.
The first step to stopping is to getting out of the habit of talking without thinking.
plan what you are going to say before hand, or literally just take a pause before you talk, taking a sip of a drink is a good way to give yourself a moment to think of what you are going to say, that way you have something in mind and aren’t just making it up as you go along.
for me I had undiagnosed anxiety and it was my way of coping, I would talk incessantly to hide how uncomfortable I was in any kind of social situation.
I would literally just make shit up to have something to talk about.
i didn’t even realise I was doing it until it was out of my mouth half the time.
but the best thing I did was get hobbies, I started learning a language and i learned to knit, it gave me something to talk about instead of making stuff up.
I would also make mental notes of things to talk about, a tv show I was watching, things in the news, I’d actually research things like news stories or historical or geographical things so that I had specific talking points.
once you break the habit of relying on the fantasist part of your brain to make conversation it becomes so much easier to stop the little lies.