I'm fleshing out a novel which seems to have enough going on without adding an antagonist. In reality, my main character is her own antagonist. She is warring with herself, battling feelings of guilt after the death of her grandfather and must work through this in order to move on. I've read the thread on writing a book without an antagonist but it seems to be suggesting that it only works in short stories, which is not what I'm going for. 

There is a romantic sub-plot, if that helps any. Perhaps I should switch to the romance being the main idea to fix this?