lying

my fiancee and I have been together for 10 years. we have 6 year old twins and a 11 year old ( from a previous relationship of his). He has struggled with alcoholism and for about 13 years and has been sober for 7 years. Things have been super stressful lately. I'm currently 31 weeks pregnant with another sweet girl. our car broke down 2 days after thanksgiving and we have been borrowing cars and getting rides to and from work while we look for something else. We have been having several issues with his daughter and her mother. Her mom has been letting her hang out with older kids (16-18 year olds) and she has been getting in trouble in school and her mom fights us every week to pick her up.

the last few weeks he has been acting strange. he's been working a lot of overtime to help save up for a new car. but lately at night he gets over tired and has been very rude to me for no reason. for example one night I asked what he wanted to take to work for lunch the next day and he tells me to "stop fucking nagging me". at first I thought he was just over tired but last night he was sorting his tools out in his work room and he comes upstairs all stumbling and slurring his words. I hate even accusing him but I asked if he had been drinking and of course he replied no. He reeked of what I thought was alcohol and when I mentioned that he said I was being ridiculous and it was just mouthwash. Then he laid down and passed out in his work clothes. So I went snooping and found two small empty liquor bottles...

I guess I'm looking for advice on this. mostly I'm hurt. why didn't he come to me if he was feeling like drinking and why lie to me? The one thing him and I have always had is trust he was honest with me when he started recovery. I don't really want to fight with him and I refuse to argue in front of our kids.