i have been at every oppurtinity but it doesnt seem to be working. maybe i need to do more?
It definitely could take a while! It took me a couple months ingame time to get a Master, for example. I think it goes faster if they have a naturally submissive personality (shy/insecure/passive people are more likely to be your sub then forward/aggressive/confident people) and of course they need the Submissive or Switch inclination.
A Dom/Sub relationship IS a romantic relationship, just with added mechanics. So if you're in a monogamous relationship (with a boyfriend/girlfriend or open partner) you can't also have a sub. But if you have the polyamorous inclination you can have as many poly partners and doms/subs as you want. You get the polyamorous inclination by starting with it, completing the Best Friend questline and choosing to be poly with them, or by cheating and giving yourself the inclination.