It sounds like you need to find yourself.
This has been a problem for me in the past with lovers. Their perspectives overtake my own. I am trying to regain my ground again after this assault on what had felt like a very clear and confident conviction.
If that is how it used to go up to now, you have some soul-searching to do. And you should take your time doing so. Learn to listen to yourself, to your desires and needs and try to find who you are. For now, even if your polyamorous ideas won't come true for some time or if you find a whole different kind of relationship, it would be an enormous gain to finally know WHO YOU ARE and WHAT YOU WANT. That's what poly does for most people discovering an idea not entertained by the masses: There aren't that many who try to define how your life has to be and how you should behave or think. You will have to find your ideal, your way, your life that proofs to be just right for you - not because someone tells you that this is the way it should be.
I have struggled with this process for years while living with my husband, whom I loved dearly. I didn't speak up because I was afraid of hurting him, because I was still processing my wants and needs and finally I found that I couldn't stay my 'old self' any longer and I tested my feelings out and talked to him and we began our 'poly journey'. He choose to stay with me. He still is mostly mono (even though I guess he started thinking poly already himself). My other partner is clearly mono (body and mind). Different relationship approaches can exist side by side, so stay open to the possibilities and start searching for the right way for yourself.
Facts: 30, female, bi, v-type relationship with Sward (husband, straight, mono) and Lin (boyfriend, straight, mono), poly-fi and co-primary.