Hey! My name's Drew and I'll be of assistance today.
When it comes to summarizing stories I feel that it is best to seek outside sources to go along with the reading. Nothing substitutes reading the context but I too personally know that even after re-reading stories I don't always have a full grasp. I haven't read the book you are reading but I can reccommend checking out sites like cliffnotes and shmoop. Both give great summaries chapter by chapter and make understanding the key themes a whole lot easier. Check out these links and let me know if they help.