I'm hiding a HUGE secret from my mom

So let me tell you, I'm 19 about to be 20 and I'm in a relationship with a man in the Marines. Now here's the secret I am getting married in 2 months. I can't tell my mom because she hates him. She tells me day in and day out that if I marry him or have a baby with him to never contact her again. This for me is completely heart breaking and is hurting me. I want to tell her and I want her to help me with my wedding plans. (I'm getting a courthouse marriage and actual wedding next year) I want her to be apart of my life but I can't continue with the negativity. She is so negative and so toxic and I feel as though I can't even be happy around her. I feel like she drains me of everything. She doesn't even want to let me move out. I am trying to be happy and move on with my life but I don't want to hurt her. She's my mom and I love her but I'm an adult and the toxicity of being around her is getting to be too much. Am I in the wrong?