hey there. first of all i'd like to apologize for any mistakes since english isn't my first language. i hope someone can help me with my problem

so here's the story:
i am a very lonely person. i don't really have friends, and making connections with people beyond the usual small talk is really hard for me, since i'm a super closed person. but i have this guy friend. we've been friends for the past 3 years and we're kind of close. but the problem is i think i'm sort of obsessed with him. i don't want to date him or anything, but i have this irrational thing going on in my head where i really wish i was his favorite friend, since he's my favorite one. i really care about him and make sure i do anything i can to help him in anything he needs, and i know he cares about me too, but not even close to the way i do about him. he's got lots of other friends he constantly hangs out with and i get super jealous, to the point of putting me in tears thinking he may like them more than he likes me, and eventually will forget about me. now i'm really confused and don't know what i should do, because this whole situation is making me feel miserable, and sometimes i think it would be better if i distanced myself from him for a while. but at the same time i think it would be even worst, because i have this need of talking to him constantly, and that's the only thing that makes me feel better.

what should i do? has anyone been through something like that or have some advice?