"How can I not feel so lonely" boy If any of us knew how we wont be on this site, loneliness is not the same for everyone, some people have family and friends but they feel lonely, other people have friends and a healthy life but not having a couple make them feel lonely, other ones have literally no one so their loneliness is more than obvious, in resume, you need to find what is that makes you feel lonely is that you have no couple, no friends, no family, or is just something in your head that makes you feel that way even when you have a good life
and about going to bed late, lonely people have insomnia mostly because we usually dont have any plans, most of "normal" people also stay awake until late but they do while having a social acitivitie like going out, visintg friends, a couple, chatting with friends, etc. so going to bed late is not "weird" is just that doing it by yourself will make you feel lonely, maybe going outside instead of staying in your bed will help