Who am I?

A very philosophical question for this early in the morning, but I suppose a valid one. I mean am I me because of genetics or is it because of what I have been through in my life, or is it a combination of the two? And on that line of thought am I in this place mentally because of a "chemical imbalance" or is it because of the way I have been treated by others or is it something that happened to me as a baby? And I don't mean anything bad but just the fact that I didn't get enough attention or I didn't bond properly with my parents.
I suppose it's that age old question of nature vs nurture and which one dictates the human you become. I suppose I think it's a combination of the two, which I think is the same for anyone in this world, but that then leads to the question of why was I verbally bullied at school, what was it about me that led the people to want to behave that way towards me. I know that part of it was the "sheep syndrome" where some people will just follow what everyone else does, but the reason behind the bullying was such an unimportant one and yet it led to name calling and people refusing to stand near me, little things but enough to make me feel inadequate and suspicious. Actually to be correct I don't know for sure what was behind it but from where I stood it seemed to have very little to do with who I actually was and more to do with my dad's job which is actually just ridiculous, and yes it only lasted for a year and what was really weird was the fact that the people who started it and encouraged it were the ones to put a stop to it.
Actually thinking about it, it is amazing how many things that have happened in my past do still dictate how I react now and maybe that is also why I can be quite immature for my age.
It was reading another blog that really made me think all this, as it made me wonder what emotional baggage I carrying with me and whether or not I could actually really deal with it and face the problem before putting it behind me. As I know there are things in my life that I have never really faced and when thoughts about them do come to the surface I just try to ignore them and I distract myself from them by self-harming. Maybe, just maybe, the reason why I feel inadequate and useless is the fact that I dropped out of uni, not once but twice. And so I felt and still feel that I let my parents down, even though I know that I didn't and that they have always supported me no matter what, deep down I seem to feel this need to prove myself to them and yet I know that they are so supportive of me and that they would never judge me or stop loving me and yet that is the one thing that I am convinced will happen, I just keep expecting them to turn round and just say that they don't love me anymore. But that won't happen if they haven't said that already after what I have put them through then I know that they won't do so now.
I guess that it is right that sometimes just letting the thoughts out can help you to deal with what is happening, but then again that is the basic premise of counselling or at least some types of counselling. And I suppose that writing here means that all these thoughts which I would normally never verbalise are put out there for anyone to read, which allows me to talk without really talking. I suppose that what it does is gives people the real me so that they can think whatever they want but at least they have the full truth to work with rather than just the small amount that I usually give.
Maybe what I should do is let the thoughts out so that I am no longer burdened with them and I can finally be allowed to fly and reach whatever potential I may have.