Alcohol and drugs only weaken the mind, give us a feeling of pleasant freedom and lightness for a while. But this has a price, and a disproportionately high price. There is no point in ever trying drugs or alcohol at all.
To understand "who am I", you need to understand several concepts.
I will try to explain simply:
There is a brain, our physical body, many more subtle-material bodies (etheric, astral, etc.), Mind, Soul and Spirit.
1) The brain is a receiver that receives information from a single information field. Some are better, some are worse. Many scientists and creative personalities saw their inventions and discoveries in a dream. Creative individuals also do nothing themselves, they draw this from a single information field, because they have greater access to it. But the brain is definitely not me.
2) The physical body is a material vessel in which we can be in this world to get our experience
3) Other bodies (astral, etheric and others) - are needed in order to gain experience in more subtle worlds. For example, when we think, we are already "traveling" through one of the worlds in our subtle body. Each of the bodies is needed for its own purposes (and we all have them, it's just that in the modern world we have ceased to see and feel them). But this can be fixed. So, these bodies are not me either.
4) The mind is a stream of thoughts that comes from a single information field. It can work for us or against us. The "devil" is also there. Therefore, we need to control what thoughts we give the green light to. We need to use it for good. But a single information field or our individual mind is also not me.
5) The soul is one of the shells of our body (one of the subtle bodies), but this body don't belong to this material world (unlike our other bodies, including the astral, etc.). The soul is a part of God (creator), it is boundless Love, it is good, conscience, it is all the best and brightest. We all strive to do the right thing, according to our conscience, but the "devil" in our mind distracts and confuses us. It should be so. This is necessary so that we develop and consciously come to God (i.e. to our own Soul through Love in different manifestations). But the Soul is still just a part of God inside each of us, it is not me yet.
6) Finally, the Spirit is me. This is what has always been and will always be, it does not obey the laws of time, it cannot disappear or die, it is always there. Here in this material world with the help of the mind it will not be possible to realize it (only if with the help of other subtle bodies). To put it simply, it's like a multi-layered spacesuit so that we can be and do something in an aggressive environment. We (Spirit) materialize in this material world for our development and experience, to merge with our Soul (and stop reincarnating here). Then we become one level higher (an angel or gods, you can call it differently, the essence doesn't change). We come to the material world in our series of reincarnations as an individual, and we leave it as a person (i.e. with the experience of Love, i.e. merge with the Soul, with the inner light).
This is, if in a simple way, so that everyone can understand. This information is available to everyone. It said the same thing everywhere (any religions, Vedic knowledge, philosophy, different teachings, even science, etc.), just in different words for different people who lived at different times, etc.