Hello there, thank you.  I'm plenty experienced with the Rue/DMT combination, and I feel confident it wasn't the Rue, though the Rue's effects were pronounced in other areas of the experience.  I felt like I took a physical hit of an AWFUL chemical, that's why I assumed lye, but found other people saying this could be due to burning DMT.  Perhaps I burnt a lot of it, inhaled it, and got spooked, but it was scary.