I want to join the Military but im worried about my mom.

I want to join the military because I think it will be good for me both physically and mentally not to mention it will help me pay for school if I choose to go. My only problem is that im worried about my mom if I do. She’s 43 and she’s a single parent, she had my older brother when she was 20 and myself when she was 22. She then got married and had my younger brother who is now 13 and my younger sister who is 6. My mom divorced my stepdad about 5 years ago and she’s been single ever since. Times are rough right now with money and she struggles to pay bills. I give her money whenever I can sometimes my whole paycheck, my older brother helps maybe sometimes when he wants to but I feel as if im the only one helping her. I’ve spoken to her about my wanting to join the military and she does not want me to because she thinks I will get sent to iraq or afganistan. She told me if I died she would die too and that hurt me because my mom means the world to me, she’s been the one constant in my life and motivation for a lot of things she’s the only parent I’ve ever had, my father was never around. I know I want to join the military but I hate myself sometimes for wanting to because I feel that she needs me and if I leave her I will make things worse for her and add another thing for her to stress about. But I also know that the money I get could greatly help her (although its not why I want to do it, it is a plus) what should I do when what I want will hurt her and what she wants will hurt me?