Is it normal that i'm doubting my relationship at this point?

My name is T and I'm a 21 year old male. Just recently I found out that my High School sweetheart of 9 years is pregnant. I am without a doubt extremely excited to be a father! It's just that I'm doubting wether or not she and myself should be together anymore. I feel as if the love has been lost for a very long time and that we do and always have brought out the worst in one another. We fight constantly, argue and have even been known to have pyhsical confrontations. I am ashamed of the way I've acted in the past and I wish that we could somehow just rebuild our trust, but we've tried many different things and I feel that we have just stayed together out of convenience and familiarity. It's my belief and nightmare that if we were to stay together and raise this child together we would end up destroying one another and in the process the life of my unborn child. I grew up in an extremely dysfunctional house hold as a child and I know all to well the trauma that a bad relationship between adults can cause a child. I do not want this, I do want the child and I will support her for the next 18 years without question, I just know that we are not meant to be together. She was my first and true love and I will always love her, I am just not in love with her. I am so conflicted right now, I am scared of the judgements my peers would have if I were to leave her while pregnant. They don't know what goes on behind closed doors though and they don't understand the hurt the we have inflicted on one another in the past? Does anyone have advice they could offer?