Hey - I suffered with similar thing for a long time and was scared of it just like you. I know exactly how you are feeling. It is a scary thing and the self is a concept that we will never truly understand. But I can tell you it gets better with acceptance and patience and things we don't understand don't have to be scary.
I know it seems scary and so overwhelming but it is only that way because you are hyperfocused on trying to figure out something that you never will be able to truly understand. When you are solely focused on the voice in your head you become just that - as it is all you are aware of and thinking about at the moment. But in reality and "normal" thinking you are not so focused on over analysing what you are - you are focused on numerous things such as daily tasks and your surroundings and you get back into a flow state and begin to experience life as a full picture. Your experience of life is not just that voice in your head, it is everything around you, you are a part of everything. Trust me I was the exact same as you, I made myself miserable trying to figure everything out. It is important to understand that you won't figure these things out but instead have to train yourself to accept them. When you are in DPDR your whole everyday experience is just lived inside of your head question anything and everything - and when it comes to the very thing you are questioning with its like a short fuse! I promise it gets better, and eventually you will get back into a flow state of thinking where you do not even "think" about thinking anymore, you just live life and experience it without trying to explain and analyse everything about yourself and reality. I used to feel the exact same as you and I wanted to escape my mind. Once I realised that DPDR was based around my anxiety and obsessive nature latching onto anything it can to be afraid of and obsess about I took steps to try and calm that anxiety things eventually got better and I promise they will for you too.
