There are plenty of obstacles that come naturally and normally to marriages. They include illness, death, finances, family issues with in-laws, children and careers. Those are big obstacles sometimes, and they’re obstacles that usually stagger over the course of a long term relationship. That you are fighting so bitterly so soon after your engagement is of concern. 😕 While some people over fantasize what an engagement or a wedding should be, it sounds like you don’t have that problem.
What are you both fighting about? Is it something that can be resolved?