I agree with what Henreh and Nibo both said ... now I am sorry but I think I wrote a post longer than yours.
Sounds very much like a situation I was in ... But let's not worry about that for now. I am sorry if it seems like I am bashing everyone in your family ... but I am just expressing my perspective, just as you had through out this. I can't faully grasp 13 years worth of issues, so please bare with me as I write this.
But your mother is not the only one at fault, you also have to understand that your father has some role in it. A relationship requires two people to work together. Until those differences are worked out, even if they did get back together, that won't instantly fix years worth of pain.
If your father decided to drink to hide from issues rather than discuss it with her, I'm afraid that it won't work. I don't mean to bash your father ... but he's the one who should be trying to talk to your mom, not you.
For your mother, you have to understand her position ... she is doing her best to raise you all up without a husband. You don't have a father, but she also does not have a husband. You are all in this together ... so please remember that. My father was like that to my mother, it can feel really hard when it seems like the whole world is against you ... and for alot of people their family is the world.
If you wish ... perhaps you can try talking about it with your father? I got into a lot of bad situations by trying to delve into my parents matters ... but despite that pain I don't regret it. Now, please don't throw yourself into a dangerous situation. If he was willing to beat your mother, I really don't want to see you get hurt.
And don't take having no father for a childhood to heart. I know it's difficult, especially being raised in a world where everyone should have the "ideal" 2 parents, but life is not always like that. Your mother is doing her best to help you both
Years are only numbers, your brother can grow to live to be a thousand and still have those feelings. I understand your position though, my mother is quite paranoid about a lot of things. She would like never let me out of the house to visit friends til i was like 16! ( Sobs ).
You're a nice person for being so forgiving ... so I really don't want to see a person like you get hurt.
And to be honest
Because my brother got to know with violence pretty early, he often used it against me, forcing me to do things I don't want to. I really hated him back then, I should still do but I'm not really the person for that.
That statement frightens me to be quite honest.
That is very much how I view it ... and seeing how he acts, it is ultimately up for himself to understand his issues. You can try to help ... but as I said, I don't want to see you end up getting hurt.
I understand if he's hurt about not having a father ... but that was years ago, he needs to be able to move and get by with what is going on.
And I hate to say it, but perhaps it is time for you to move forward as well? You won't get out of the tunnel if you keep turning back and waiting for the light to come to you ...
It's not easy. Do you have friends or other relatives who can perhaps help you move on? Perhaps they are not able to replace your "family", but I am sure you know of some people who act as one. I am not telling you to abandon your family, but rather finding people who can give you strength or hold you up when you need help. Someone or some people who can lift you up so that one day you can return to help your family.
I am sorry if I am sounding cheesy or corny, but that's how I moved on with my life.
So please take care, if you need anything don't hesitate to ask. I'll do my best to help even if I don't know you.