Back pain, by itself with no lesions, is not a symptom of herpes, no. I don’t know what websites you are referring to but I doubt that any would say that by itself is characteristic of genital herpes. Nor is lightheadedness .
Your questions are fine – that’s why I am here. But we must go back to the sexual experience you are worried about. The things you did just didn’t put you at risk. Your scrotum touching her buttocks, with no lesions present on her buttock especially, is not a risks. Even if she did have lesions on her buttocks, I wouldn’t say that is much of a risk at all!
Terri