The Unintended Mentorship That Felt Like a Mistake

I'm in my mid-50s and I've recently come to terms with something that's been gnawing at me for the past few months. About six months ago, a new student joined my university course - let's call her Elizabeth. She was shy but incredibly eager to learn everything she could about our field of study. Over time, we found ourselves chatting outside of class, sometimes over coffee or lunch. I should clarify that I'm married and have always been faithful to my wife. However, Elizabeth seemed drawn to me in a way that made me uncomfortable but also intrigued. Our conversations would often take an unexpected turn into more personal areas. She began confiding things in me that she had never shared with anyone else - family troubles, insecurities about her career path, and the overwhelming desire for guidance and support. I found myself increasingly invested in helping her navigate these challenges. It wasn't until a few weeks ago when we were having one of our conversations at my home (which was completely out of character) that things shifted dramatically. I had invited Elizabeth over to go through some course materials she'd been struggling with, but what started as academic support soon turned into something far more intimate. The line between mentor and student blurred in a way I hadn't anticipated or intended. I've since pulled back significantly from our interactions, feeling both guilty and confused about the situation. Is this normal? Am I just an aging man struggling to connect with someone who craves guidance, or did I cross a significant boundary that I can never undo? I'm looking for advice on how to handle this situation moving forward - whether it's cutting ties entirely or finding some way to maintain professional boundaries while respecting Elizabeth's needs. What would you do?