I think theres parent (the noun) and parenting (the verb). Society puts a lot of emphasis on the former and not a lot on the latter. It sounds like you are exceptionally good at the latter but the former is dependent on circumstance.

There are thousands of children who need the latter. Please look into being a foster carer or adopting, the capacity for love is endless and we’re past the point of presuming that all foster children need a nuclear family (some do) but many don’t. You might be a perfect fit for another soul, and years of auntie-practice will stand you in good stead.