I’m in love with my best friend

So I have been in love with my best friend for 3 years now. I’ve never had eyes for anyone else, I’ve never told them and I’ve tried to get over it but no matter what I always go back to them. The worst part is there’s times where the love feels reciprocal, they’ll make flirty jokes, pretend to be a couple and even suggest wearing couples Halloween outfits. And all that sounds great right, except this is short lived, every month without fail they find someone to crush over, since I’m their best friend they tell me of course. They’ll tell me all about how pretty they are how perfect they are and I just smile and nod. It’s never normally that serious but recently they’ve been really obsessed with someone new they know. And I really thought we where getting somewhere I mean, our flirting became so obvious even our other friends could tell and then out of the blue they start describing this girl they’ve been talking to. It felt like such a hit in the face. And I cried every night they’d talk about her. I wish I could talk to my other friends about it. I’ve been leaving them on read most days, other days I can’t get out of bed. It’s so stupid i just wish I could get over them. I feel led on In truth, but I cant make force them to love me. How do I fall out of love. I’ve been trying for years I just want this to be over but they always drag me back in with their flirty words. I hate this. I hate them and I want to just shout in their face. I do everything for them but I guess that’s not their fault that I loved them so much. Oh well there’s nothing I can do