I have 3 children myself and reading your post was...to be honest, it was hard. Your post is definitely written by a person who is not a parent. I don't try or want to judge you since I understand you could never understand the point of view of people who have children. You are clearly confused, both of you, and like someone else already told, you two should chill out and think this over week or two. I also want to clarify my opinions are 100% outside of religions.
This is important decision that cannot be reversed. And no, even if you or the girl deeply regretted abortion in the future, it is still the child who lost the most, not you two.
Never ever think that you could not be a good parent or that girl could not be a good mother. Never.
Never think money would be a problem. There is a solution, you two can make it work.
Never think a child would ruin your life. That is some of the most fucking selfish entitled bullshit I have ever heard.
Thing is, a child changes you as a person. I dare to say, if you someday become a parent and then would read your original post, you simply would not regocnize any of it. A newborn baby's first cry, the cry of life itself, has the power to completely change your understanding, the beliefs, the whole reality you are living. It happened to me, like a newspaper shredded before your eyes, my reality crumpled and I could see and understand something more, something that was always there, the deepest emotions.
Take a breather and think this over.
The thing is you did it with someone you love he obviously doesn't like her. (which doesn't make sense why you would have sex with someone you don't like.)