This same question has come up a few times in this forum.

As the coal miner said after the cave in, "Things ain't looking to bright, and it's dark too."

You can play at being a submissive or a dominant, but if the desire isn't really there it's not something that is going to suddenly pop into existence.

In my experiences with others in the same situation as yourself, you need to decide how important BDSM is as a part of your sexuality and go from there. If it is an important part then your boyfriend needs to get with the program, or you need to get a new boyfriend. If it isn't that important then a little "self indulgence" while reading the stories here on the site may suffice.

Good luck.