I just found out he’s divorced, SOS!!

So my boyfriend and I have been together for 8 months and we dated for 3 months before becoming a couple. Between those 3 months we started to get to know each other and of course I asked him if he’s been married before and his answer was no. He never thought to mention that he was in 2008 for 6 months and the divorce never got filed until 2014. I just found out about this yesterday and as soon as I found out I talked to him about it and he denied it, he said it was only for a month and that he was drunk. I took pictures of the divorce documents and it said that the duration of the marriage before the separation was 6 months. He did not know I had the documents so he lied to my face saying it was only a month. He’s saying he did not mentioned it because he didn’t think it was important and that it didn’t really count. I’m not mad because he’s divorced I’m mad because he’s been lying to me and my family that he’s never been married. I love him but I don’t know if I can stay with him. I don’t want to let it slide and for him to think he can lie to me again. I’m confused I don’t know if I’m exaggerating or not. Please let me know what you think I should do.