I need your opinion girlies

I've been with my boyfriend for about five months now, but i've loved him for three years. according to him he's loved me for that long as well but recently, i came across his chats with his ex(ik i shouldn't have done that) and i felt like our relationship is just a carbon copy of their relationship. He said the same things that he says to me now to her; uses the same references, the same songs. Honestly, I love him so much but I don't think i'll ever be able to get over this. He says he loves me so much and that i'm the love of his life but unfortunately i can't believe him. Plus the things between him and his ex happened when he "liked" me too apparently. What should I do? If I confront him about this, I feel like i'll get gaslit.