The solution of the age dependant separation

Our predicament of boylove hasn't been easy to deal with. My nephew grew older about a year and a half ago and it has been extremely difficult since then. I posted about it several times here on BC and discussed it on LL but the void and the disconnection don't get any better. It is so difficult because I can't explain to him, or to anyone in the family, why I have suddenly become unapproachable to him. He made me get out of bed when I was at my lowest and my life changed ever since he entered my life, but now it is absolutely chilling when I am around him. The spark and the connection have gone and I struggle to feign excitement when I am around him. It is so unfair to him and it is unfair to me. I know many here have brush this off as something not significant arguing that I am still his uncle, but I never ever took the role of an uncle. I think parenting and having kids are the stupidest idea in the world, to put it mildly, so I don't want to hear this bullshit. How do you deal with a little friend growing older and being devoured by age? What explanation do you give to him and to the people around us that I am not interested anymore as before? It is a very crushing feeling to feel the weight of the world and trying to make a relationship where once was but it's very difficult to have it anymore. I see him and I long to the old days. I wonder how he feels when he sees me so distant and still caring for his sister the same way I once cared for him. I find no other way than, one day, people will understand us the way we are that we are absolutely brilliant with the kids from a certain age to a certain age then we have to move on and the kids have to move on. The same way that people, reluctantly, understood that certain men loved women but not in a sexual way, there will be awareness that age dependent attraction exists and beyond a certain age window, we are unable to be there for our loved ones. I see no other way other than saying it clearly that we are boylovers and can only provide from a certain age to a certain age. This, of course, is very dangerous to do at the moment. Have you found another way to heal the wound of age dependent separation?