Dear Asad, it is difficult to read a short history over the Internet and offer a diagnosis. You mentioned bipolar disorder as a possible diagnosis and based on the information you have revealed, that may be a possibility. A personality disorder may also be possible. If I had the opportunity to interview you in person and ask you many questions, it might give me a better sense of what you may be suffering from.
I generally contend that knowing your “exact” psychiatric diagnosis is not always important. If you are experiencing problems that hinder or stunt your psychological development then some action needs to be taken. In such instances, therapy should be considered.
You have lived a difficult life and have many challenges. You’re impulsive and forgetful, by your own admission, and have a short temper although the anger you say you can control but sometimes choose not to. As you may already know, anger can affect your ability to have good relationships because few people like to be in the company of angry and unpredictable people. Your sisters have schizophrenia, a disease that is notoriously difficult to manage and usually takes a toll on the family. As you said, growing up in that chaotic environment had a negative impact upon you. Your father was emotionally abusive towards you and others and this experience undoubtedly left you scarred. This could explain why you experience emotional dysregulation.
Most people enter therapy as adults because of problems that stem from their childhood or their upbringing. It is probably the number one reason therapy is needed.
The issues you wrote about are correctable and should be treated. You may benefit from medication to help control your impulsivity and therapy could greatly assist you in the emotional issues you struggle with. You may be able to learn how to respond appropriately to certain situations. Therapy would also help you with your low self-esteem.
I am sorry that I could not offer you a more specific diagnosis but I do think that if you are willing to seek help for your issues there is a good chance they can be resolved. Thanks for writing.