Characters. If the reader cannot relate to your characters she will not continue reading. She may love them or hate them, but the author has to draw the reader into their lives so she keeps reading. If a character is Too Stupid To Live (eg. walking alone into a possible murderer’s house) you will lose the reader right then and there.
These days, female characters are expected to make an effort to solve their own problems. The hero may still come riding up on his white horse to sweep her away, but she should have been endeavoring to solve her own problems, not crying in a corner and wringing her hands.
Plot. There must be a plot. It is through the plot the characters show their development and build their relationship. In an erotic romance the sex may be part of the plot, but there must be something else happening as well—a bad guy to defeat, the world to save, or whatever.
If you are marketing your book as an erotic romance there must be detailed sexual encounters as well as hot, steamy looks. Otherwise what you have written is a mainstream romance.
Fiction writing is a very tough, competitive world. Give yourself an edge toward success by having Helen edit your book. Rates on application.