Welcome to the forum you will find great help here.
I notice you mentioned that you like the idea of a support group but religion puts you off. There are secular support groups out there, a google such should turn up some of them in your area. If a support group is something you are comfortable with then I imagine it will be a great resource so definitely go out and find one.
Having drunk for so long from such a young age you are facing what must seem like a big challenge, but remember that all challenges can be broken down into manageable parts. Identifying triggers for your drinking, any root causes and developing various techniques to cope with cravings are all things you should look into. It sounds like you are in the right mindset, you are ready to stop, so maybe look into AVRT or similar secular systems.
You worry you won't bea fun person. Well let me tell you that when people are drunk they think they're fun people, but usually they're just obnoxious. I've spent nights with friends completely sober while they drink and it really brings home to you how pathetic you look when drunk. But when you're the drunk one you think it's great, that you're all having fun, without realising you look like an idiot lol.
Having fun is perfectly possible when sober, actually I have more fun when I'm sober, and I actually get to remember the night! I always get amazed when people tell me they had a great night but can't tell me anything that happened because they blacked out. You say you cry and get angry when drunk, well that doesn't sound fun for you or your family, but you're telling yourself you are having fun. You need to realise that's a lie, conditioned into you by society who tell you that you have to drink to have fun. You can do this and believe me once you've recovered for a few months you will start to see your mood becoming way more stable. Alcohol causes very real, physical changes in the brain that are reversible if you stay sober.
Your family history is worrying, you of all people should know how horrible liver disease is. Not a nice way to go, and you have kids which I am sure you want to see grow up and become fine people.
Good luck.