I'm the wife figure and my guy left me for a girlfriend

And she treats me with total disrespect. She gets in his phone and hits laughing faces on my messages. She acts like she's better than me. She controlls his every move. She acts like she's so important and that I was nothing in his life. I know better than that. I was definitely a significant connection. He wanted to marry me, he loved me, but I was too old for him so he went off with some 5th grade mindset. I feel like it is just some karmic lesson he has to learn in order for him to finally have appreciation for me