"You can't change who you are".
I've heard the above statement enough times before, and it couldn't be more wrong.
People people change all the time, and as situations change, their perspectives change. You can change yourself for the better if you work at it. Have grit and overcome your problems. Of course a prerequisite for that would be knowing what they are in the first place. So from this point on, ask for feedback and make sure that people are being honest with their feedback and are telling you what you need to hear.
Work towards the things that are holding you back. Change who you are for the better everyday.