oh also ellis lives alone because he's a bit disillusioned with society on the whole, particularly after a childhood of basically being let down a fair bit (for one thing he's mentally ill [+ maybe queer] and he didnt grow up in an understanding or accepting environment at all, there was a whole lot of being passed around by various people attempting to ~fix him and much of it was w/ a very 'kill or cure'/'tough love' approach so)

also just the mental illness aspect of things in general... he's prone to anxiety attacks, manic & depressive episodes at times etc, got poked around at a lot for it by people who thought it could just be overcome or believed him to be faking it and after years of being constantly forced out of home to interact with others in situations that v often proved v distressing to him he's just gotten sick of the whole business of social interaction in general

he does want to be able to get along with people a little deep-down hence the lingering loneliness but it's a much smaller part of him than the part that doesn't want to have to live with the many negative parts of society that keep crawling their way back into his life just to experience the few positive ones here and there. so once he was able to he just... upped and left i suppose

he didn't really think it all out very well though. food and clean water and clothes and all that, he kind of took most of it for granted so yeah now he doesn't eat or drink much just due to the sudden lack of it as a ubiquitous commodity, just cycles through the same handful of clothes again and again as necessary, personal hygiene upkeep is just plain not completely a thing anymore (although he doesn't mind that one too much) etc