Wanting kids...

My boyfriend is an amazing guy he is so good to me and he is funny and handsome and more then I ever could have asked for he is my everything and just a genuinely good guy. We have been together a while and I went into this relationship thinking we both wanted kids... well it turns out recently he said he doesn’t want more kids (he has some kids from his previous relationship) my heart is breaking right now and has been ever since he told me that. I want him to be able to come to me and tell me how he really feels which I’m glad he did. I was never really was serious about wanting kids until I met him.. and we used to talk about it all the time. I don’t know what changed in him. I know I need to talk to him about how I feel but I want to decide if it is a deal breaker for me.. although deep down i know it’s not. I can’t see my life without him he is my soulmate and I feel like I am either gonna have to loose him or loose having kids I don’t really think I want kids unless it is with him. I have just been rethinking everything lately because of this and I want to talk to him about this so bad. But I feel like I need to decide what I want before I bring it up and every time I try to talk to him my mind goes blank and I have no idea what to say because I am unsure if I should just deal with it myself and get over myself or if he will change his mind eventually again but I don’t want to end up resenting him down the road. And I don’t want him to feel like he will loose me if he doesn’t want kids or trapped if he ends up having kids with me. So I just have no idea how to bring this up and how to talk to him about this I know how he really feels now I’m just heartbroken and I don’t know if I should feel like this but I almost feel betrayed. I am not good at communicating my emotions and I don’t know where to start please help me figure out how to talk to him about this like how to bring it up.