Need help and advice with a pantyhose/stockings fetish?

There is nothing wrong with having a fetish. Dont dump on yourself for having one, just control it and keep it at a healthy level and dint let it become a complete obsession. It is good that your significant other helps fulfill your fantasy, but be honest with her about it. As far as how it developed, there really is no telling until you seek the assistance of a trained professional to work through any deep seeded issues you may have. You described the memory as being non sexual so some how you grew to correlate panty hose with sex. Keep it healthy, be honest, and I'm sure pull be fine. Good luck to you.