Scared for my future marriage?

My boyfriend and I have been together for almost 3 years now, after this year finishes it will be fully 3 years. He's seventeen and I'm sixteen and were ready for marriage (after we finish school of course), we speak about it all the time and he seems excited and comfortable about the idea and so am I but I've watched many many marriages crumble before my eyes since I was 5 my sister went through a terrible divorce just recently and lets face it my parents aren't the perfect couple they argue almost everyday avoid each other for months and my mothers to blame, all this has a profound effect on me and how I perceive things. It's not healthy for me to grow up in this kind of environment how can I give the proper affection and family bond I never fully received to my children? My mother has huge anger issues, complains all the time, never fully satisfied and just wants more from us all the time and no matter how hard we try it's never enough for her; the worst part is I have a hint of her characteristics and this is why I'm so worried. I don't have a solid married figure to look up to and am so afraid my life is going to end up miserable as it is now since all I do is worry about this:( I'm concentrating on my studies and doing everything I can to earn my self an education and so is my boyfriend, my relationship with him is amazing he's not just my lover but above everything else my best friend I wouldn't swap him for anything but its hurting him that in the long run I wan't to avoid. I just don't want to end up like my mother. I know its so long and I appreciate your time and effort for helping out I just need some advice thanks