If it's your first comic, you should probably focus on a very short story or many of them to learn about your craft and how to collaborate with others. It is only much later as a professional that I have allowed myself to work on an open-ended project like Johnny Bullet. I would never had been able to pull that off when I was younger.
You're simply face with someone who over committed. By now, the relationship is so bad that you should just forget the two pages done and move on. It's only two pages and the script was altered. It is not your story anymore so don't focus on that. It's a waste of energy and time.
I think you also need to learn more about script writing. A three chapters long prologue is not a prologue. You need to pull off from the world building and focus on a tiny story in your universe and run with that. Go from point A to point B. Forget about the universe. You are still young and can comeback to it later. You may find that in five years, the whole universe that you created is not as interesting as you thought.
Also learn about spacing. It seems that you are writing the kind of story where you introduce things slowly. Don't. World builders always do this. Every one can create a world. But not everybody can tell a story.
You'll notice that here, I am focusing on you as opposed to the artist that you are "working with." I think that YOU have a lot of growing up to do. First you should have dumped this person months ago. Second, asking yourself whether you can salvage this at this point after the shouting and the curse means that there are self-esteem issues going on. It's bad a relationship, let it go. Get up again and focus.
There might also have been things that you set up which made the other person react this way. Now, you did not tell us what you said exactly. We only have your word. The other side of the story, if we asked the other person, it may seem very different. What you think was polite may not have been. Who knows.
The most important thing is write a short story first. This is the one advice always given to new creators. You are not ready yet to take on large projects. You are not a well-known writer, have no money and so on.
Is there a shorter story that you can focus on?