I need help really bad y’all 😩 please read

So me and my boyfriend have been together for a little over a week and have been talking for two weeks. And my best friend used to talk to him and so I told her the other day that we were together and thankfully she wasn’t mad but she did tell me that everything he says is a lie. Like for instance that he’s not 15 like he told me she said he was 14. And that he don’t live where he said he did. And also I was on his moms Facebook the other day and I saw a picture of them and someone commented and asked how old he was and she said he was 13 and this was back in April and his birthday is in December so that means he would still be 13. I’ve tried talking to him about all this but he says like no or something and just blows it off. It’s just stressing me out so bad plus my ex is talking to me again and he was my first love and I still love him but I also love my boyfriend. What should I do? 😩