Pathological liar advice

I have been with my fiancé for 5 years I love him with all my heart but I’m supposed to marry him dec 7th and I don’t think I can , he is a pathological liar and I have zero trust for him atm, it wasn’t always like this , he isn’t the man I fell in love with , but I know he is in there somewhere , last week and several times before this I told him , I will not marry you if you don’t change the lying and he hasn’t, but I feel like he will , should I wait it out? I have the ability to wait another year or two should I wait to see if things change? I can’t really leave right now even if I wanted and I don’t want to, i have no where to go so I’m “stuck” how do I get it across to him properly that I’m done if the lying doesn’t stop? (I flat out say it ,it starts a fight) I’m so frustrated and he mostly lies to stop me from stressing but it only makes me not trust him when I catch him in one, so now I think everything he says is a lie I tell him everything, I don’t lie to him. I just want this to work and I don’t Know how to make it .my idea right now that really pisses him off is silent treatment bits it’s very childish and probably won’t do much .