I can empathise here, having maried my 'vanilla' wife. When I first brought up the subject about 12 years into our marriage, she was a little shocked and uncooporative. After this I gradually got her to attend some events, informal BDSM social clubs, play parties, etc. We tried playing, still do. but unless someone really does, click with the subject, they are unlikely to be able to carry off the role, hower much they might want to. I have a need therefore to be dominated (close enough) by a female who IS fully into BDSM. I am sure this would be accepted by her as long as she is happy about what goes on. But she cant 'let go' completely. My wife and I still go to BDSM related events together, when we can, and attend BDSM play parties, where she is now seems very comfortable, more interested, and very active. (26 years into marriage) Maybe we will find someone, she can trust enough, for me to explore that side further. I live in hope.

I'm sorry, it hasn't answered your question, but I have an idea how you might feel. Good Luck!