What you're describing is very similar to how I feel, and I describe myself as sex-favorable grey-ace. I feel some sort of sexual or sexual-adjacent attraction, and don't mind sex with my partner since it can be fun and feels good for both of us. but I'd be 100% okay with never having sex again, and I have no desire for it other than when my partner is in the mood.
but xxce2AAb (other commenter) is spot on. labels are nice because they help you find community and describe your experiences in ways that are healthy instead of "weird" or "broken", but they're not necessary to fit into and are entirely a personal decision of what labels you feel like describes you best, or whether you bother using labels at all ^^
you're just you, and that's awesome
ENM is a more broad umbrella term, whereas polyamory is focused specifically on having multiple close romantic relationships (as I understand it, anyway). ENM also includes exclusively sexual relationships or other types of non-monogamy like relationship anarchy. So, polyamory is just a subset of ENM.
Non-ethical non-monogamy is generally just called "cheating" (or manipulation, or abuse) regardless of what the person perpetrating it calls it.