I am seeking advice with my current primary partner. We had an open relationship last year and then we broke up.
Why?
She then started seeing her ex and they started a polyamorous relationship. I was then brought back into their relationship.
Your terminology shows you are intimidated by their "couple privilege." You are not in "their relationship." You are in a relationship with your gf. You weren't "brought back into" anything. Do you have no self-agency? You chose to get back with her, knowing she has another partner. You can choose to leave if there are weird conditions around dating her or living with her.
... and while I knew that there was another partner, I still saw my partner as my primary. She doesn’t see that future with me though, but wants me in her life.
This kind of V can work, where you see her as primary, but she sees you as secondary. But it sounds like she's in charge of you, dealing out ultimatums, and you go along or you're out. Her way or the highway. Why would this be OK?
I told her recently that I am having feelings of being “less,” and that I see the future as me being told no constantly. The only way for me to live with her is if I wanted to pursue a relationship with her other partner. I am not attracted to her other partner.
That's not how polyamory works. Forced triads are disgusting. Never fuck anyone you are not attracted to. If they are both saying you need to fuck both of them to live with them, you decline and move on. It's pretty simple, actually.
That is, the action is simple. The feelings are "ugh."
I do have partners outside of my relationship, but none are as deep of a connection.
That's probably because you are mooning over an unattainable person. I'd suggest you come to terms with the romance being over. Then you will probably find another person to love eventually. Someone who is available to you without weird and gross terms like, "fuck this person you aren't attracted to, if you want me."
She cannot give me the security of having a nesting partner, or show me that I have the possibility of being more than just a weekend thing, which is partially just due to schedules. But whenever I ask to see her another day it’s like the world is turned upside down, in the eyes of the other partners’ relationship with her.
I love her so much, and want her in my life, but I need more than whatever this is.
Spend time thinking about what kind of stuff she's asking to do, and maybe you'll fall a bit out of love.