Are you too far gone at the ripe old age of twenty-one?
People can constantly change and better themselves BUT is it possible to change what you have become due to unforgiving circumstances? What if you do not know how you became this way or the reason you are the way you are? How do you fix the unknown? Is it easier for others to see your faults? One hundred percent: YES! They can pass their judgment, their advice, etc. but they can never actually know or give you something of value. They can make you realise but the change has to come from you. Do you even want to change? Is it necessarily a good thing?
So many questions...plenty of time to answer them. All you need to remember is to change for yourself and not for others. Act selfishly. If you are happy, that is what is most important.