My best friend doesn’t trust me

My best Friend and I of 10 years have just entered into college together (we are freshman). I thought we had a really good relationship but I was wrong. This guy had become a part of our friend group for less than a year, and it was constantly the 3 of us and sometimes others were around, they told me they were stared dating 2 weeks ago which was fine I’m happy for their relationship, but turns out this had been a thing since October… I understand her relationship business is her own but I feel hurt she didn’t say anything to me like nothing, not even a little well I think I’m starting to like so and so, just something would’ve been nice knowing how much I tell her. There have been so many opportunities she had to tell me, anytime he was mentioned it was always a "ew never " and claimed she was disinterested. When I had asked her why she didn’t tell me she said it was because she can’t trust me to keep my mouth shut which was a jab to my heart, she said that she doesn’t regret waiting long to tell me and the cherry on top was her saying that if this friendship were to end she’d be okay because In the end she found her soulmate. I realized that we aren’t even as close as I once thought we were, and I don’t know if I should even consider her as my best friend.