If we were talking about me, I'd be saying that the reason I drank is because I had a drink problem.
The next question, I suppose, would be, what caused that drink problem? I would have to say I don't know - the more honestly I examine my past, the earlier it seems to have been present in my drinking history. It's more like something went wrong before the drinking even started so that, when I faced difficult situations later in life, a drink seemed like the right way to handle them and that drinking to excess seemed to wipe them out altogether, at least in the short term. By the time I woke up to this state of affairs, drink had become my answer to everything, and the thought of a life without it terrified me, while I knew instinctively that a life with it would be short and nasty.
For a while, I thought that, if I could fix my other problems, the drink problem would go away. Sadly, this prvoed not to be the case. For example, I drank because I was hard up and it seemed a relatively affordable pleasure. When I came by more money, though, far from stopping or cutting down, I just bought more drink, better quality drink, or both! I used to think along the lines that if you had my life (and I had my share of hard luck stories) you would drink like I did. It never occurred to me that, if you drank like I did, you would have my life.
I eventually came to a grudging acceptance that, however my drink problem had come about, I was stuck with it, in the sense that I couldn't eradicate it and drink like everyone else. However, what I could do, with help, was to stop drinking, and then all the symptoms became irrelevant.
That left me without a drink, and therefore without the consequences of a drink problem, but with a problematic life, made worse by years of hiding from responsibility. However, again with support and fortified by my improving physical and mental health, I was able to start addressing those problems and rebuilding a life for myself. As a result, I am now far happier than I ever was when drinking. The worst of my days now is far, far better than the best of my days when drinking.
Only you can decide whether that sounds like your situation or if it rings any bells or if you want to act on that. But I hope it is of some use to you and am willing to discuss it further if that would help.