kinda lonely???

hey
let’s just cut to the chase. i have plenty of friends, who i really love and who i’m close with, and yet, in spite of this, i sometimes feel really down when i’m alone. like, that bleak and empty kind of down, not so much crying. i took a couple of tests online (reliable i know) and they claimed i am mildly lonely and have mild depression. idk how accurate this is because most of the time i feel totally fine, especially with my friends, it’s just that occasionally i feel like this ie super depressed and lonely. i’m wondering if this is because i literally never share things with my friends or anyone really, i just keep quiet about all my feelings because i just hate telling people things like that. i’m also wondering if this is hitting me at the moment because i have a newly close friend who i wish i was closer to, i’ve gotten super obsessed with her ngl, basically a platonic crush, and my wish for us to be closer is also making me wish i could share my feelings with her, even though i would never actually do that irl, because as i already mentioned i am not big on sharing emotions lol.
is this just being sad sometimes or do you reckon these tests were right? obviously i know i’m not gonna get the most reliable answer anywhere online, i’m just curious tbh.
anyway that’s everything. this post doesn’t really have a clear aim, so sorry about that lol. just a vent really, not searching for proper advice or advice.