For every success story there are probably 2x fail stories so don't feel like everyone can do it but you.
That said everyone has the ability to do it but every case is different. Some people have more severe cases than others. The key is you have to be willing to do whatever it takes to become sober and stay sober. Are you prepared to do that? If you are then I'd come up with a plan. If it means rehab do it, if it means staying away from alcohol for months do it, if it means losing 'friends' then so be it, or going to AA meetings, visiting this site every day etc... Whatever it takes.
People on here can help you come up with a plan. We are here for you. My question would be what made you fail in the past? I'd start there and try to come up with a plan based on that.