Sorry to hear about this. It looks from that error like YARPP has not been able to complete its installation. Is it always that "CREATE TABLE IF NOT EXISTS" line that you see in the error logs? If so, it might be a weird issue where your php (apache) doesn't have the right permissions to create a table in the database.
If you have access to your mysql directly, you can just run that one CREATE TABLE command yourself directly, or verify that the table wp_yarpp_related_cache has actually been created.