stuck in the middle of a relationship AND I NEED HELP

So i've been talking to this guy since february of this year, it's been on and off for a while because i live in las vegas & he lives in texas and i do visit texas a lot but we've never met before. Recently we've been getting closer and closer to the point where we're saying i love you to eachother and he's saying things like i want to have kids with you and you're going to be my wife one day and i don't see this happening with any other girl besides you. he even tells me i'm too selfish with you and i don't want you to be with anyone else. The problem is that he's pretty serious with a girl that lives there. He's recently posted pictures of them together on holidays saying " my future " and " what my future looks like " and things of that nature , the girl he's talking to has a kid and he's in love with her kid as well. He tells me that he's not feeling the relationship and that the relationship isn't the problem if him and i become serious. Im so in love with him i'm to the point where im sitting here like an idiot waiting for him to give me attention when he's not with her... i unfollowed him off of all my social media because i cannot see him with her cause i don't want to see him happy with any other girl besides me... HELP I DONT KNOW WHAT TO DO ANYMORE. 😭😭😭