How does one overcome loneliness?

I just finished highschool.

It's not like that I don't have a loving family or friends, I do...

I have a sister that I can share most of my problems with but lately I feel like we're drifting away and I don't know what to do about it.. i still talk to her and I tried to act everything is normal but it just isn't the same anymore.

I have amazing friends that are these for me when I need them, my parents are nice too, but no matter how much I talk I can't help but feel lonely.

I sometimes just sit there and cry for no reason, most days I barely feel like doing anything.

I unfortunately have been suffering from SH habits for about 3 years now and I want to get better

I often have false awakenings and sleep paralysis and that makes sleeping scary too

No matter what I do or who I'm with, I just can't help but feel this constant loneliness.

Any suggestions on how to not feel that way?