SO if you want my opinion as someone who experienced this I'll give it from 2 perspectives first as a doctor:
1. The habbits with alcohol you are displaying are extremely worrying. Alcohol in itself is a cause for many mental illnesses and antisocial behaviour. You're using it in a matter that seems to be self-medication for both your depression (I assume with the "lifes better asleep") as well as sleep issues. Now it may seem to help your suffering and sleep when you are drunk but alcohol tolerance is something that builds incredibly quickly , which means you will need more to feel the same effects and can quickly lead to hazardous consumption (if you're not at hazardous levels already). It also as I said earlier precipitates the underlying issues such as depression and sleeplessness, consequently leading to more drinking and more life impacts etc, constantly spiralling down.
https://www.alcohol.org.nz/help-advice/advice-on-alcohol/low-risk-alcohol-drinking-advice Thats a link to some guidelines in my country about it. Its worth noting that I personally would not say you are an alcoholic if you simply drink more than 5 standards, I would say it to be self-harm behaviours or simply societal pressures depending on the context. I would say you are if you start to experience physiological withdrawals and have a pattern of high use.
Now as my personal experience with alcohol:
I was unable to sleep like you, and dealing with the stress of work was getting to me. So I started drinking every night when I got home after all, I deserved it after a 16hour shift right?. So what was a glass of wine quickly turned into a couple of bottles and over the next month or so my behaviours started to get more and more anti-social. I would start to go out on work nights and get drunk as possible, ignoring my now-ex girlfriend and starting to be just really distant and flirt with girls etc. Worst think I've ever done in my life is drink. I would consider myself an alcoholic although now sober, it took me losing the only person who meant anything to me for me to realise. Honestly the reason I'm on here and gonna CTB in a couple of weeks is because I lost her, Im just sorting out some final stuff. I really would say that you should try and stop drinking, its one horrible drug and can make the pain of life so so so much worse dude.
If you do try and stop I suggest getting a few days' worth of diazepam from your GP (helps with withdrawals) and also ask for some quetiapine. Its a great medication for sleeping (try 25mg? I'm on 150mg but thats getting up there and not Ideal). I'm not going to pretend to know the underlying issues or trying to stop you CTB, just help ease the problems you have atm and provide some advice and personal experience. I hope this helps.
P.S if you want to know a few more specifics of what to say to your doctor to get these meds or have any questions feel free to messagex.