These are difficult concepts to express in a second language, so, first of all, good job.
If I'm reading you right, it seems like you're having trouble with being interested in too many people at once - or rather wanting a relationship with multiple, multiple people, but not knowing if that is okay or how to maintain that. If that's true, I'd say there are a couple things to look at.
What is the time frame? Do you have relationships that have been going for a long while? Or is this a situation in which you just seem to meet people very regularly who you fall for? Is it a matter of being in a relationship for 6 months or a year and then meeting a new partner, or a bunch of folks you are interested in just sort of floating about your life all the time?
I ask this because you mention that you love how many unique people are out there. I understand that feeling. It's gotten me in trouble in the past. Poly has been great for me because i've learned how much I appreciate all the different shapes, mentalities, ages, skills, etc that people have. I used to be kind of judgmental, but my mind has opened boatloads in the last couple of years. On the other side of that coin, though, I find myself feeling really infatuated with people pretty quickly, and while I'm fine with a very fluid sense of emotion and connection, many people aren't.
Sometimes, for me, it takes a while to realize whether I'm really interested in someone or whether I'm just excited about a new friend, or just physically attracted, or even simply lonely or bored. I've learned I need to keep my cards close to my chest for the first few months sometimes, because once those initial feelings of excitement die down I have a better idea of how I actually want things to play out (or whether it's a safe situation for everyone involved). When you meet people that are experienced with poly or open relationships, or even people who are very sexually or socially open-minded, you can often get away with blurring the lines at first. But people who are more traditional or rooted in monogamy (as you seem to imply) will often have a hard time being in that position.
You seem to say that you do have a definite sense of who is more "primary" to you. Where does everyone fall in that order? What interests you about them? Is it love, or infatuation, purely sexual, purely friendly? What are you looking for in each of these situations? Sometimes it takes a while to figure all of that out, but the bottom line is that you need to be straightforward with any prospective partner from the get go. It's hard to hear "I'm interested in you, but I'm not sure if you're a friend, fuck-buddy, sweetheart, or primary partner yet", and I'm sure a lot of people will back out, but it's the only way to be fair. Everyone does have different wants and needs, and I'm sure that some of the people you're interested in will be fine with the situation you want. On the other hand, you can't expect someone who is (for instance) single, monogamous, and interested in a long-term relationship to only be involved in 10% of your life if it's not what they want. You can't pretend to offer more if you don't have it.
Not sure this really reflects exactly what you're talking about, but I do hope it helps. And I especially hope you get this worked out! It's a complicated life.