The sad story of Caesar

So guys, last year (13.07.2018) I met this girl, Stephanie, I got a crush on her after we spoke for a while but haven seen each other till 13.07.2019 wheeeen I found out she also had a crush on me and got into a relationship, I love her lots and we had some good times this ~5 months, but here come the problems, we can only meet 1 day a month sience we live in diferent cities... We got a long distance relationship and talked hours and hours at phone every day, and love each other looooots... Last night, we met at around ~7pm, and couldn't wait to be left alone even tho we were "going to a party", when the party ended we should've go take a walk in a park and... She came to the party with her best friend and, even tho we talked 1 hour earlier to leave that girl with some body and take some time for us, Stephanie stood with her all night long and gave me like an hour in total, maybe, I felt horrible cause I didn't know any body else at the party and stood alone for hours... I know this doesn't sound so bad, in the end, but imagine seeing your gf for a few hours a month and she doesn't give you that time when you can have it, I still love her a lot and she says the same but the things that happened... I don't think I am able to forget... My older brother suggested me to go talk tho other girls but I could never do this to her, NEVER. Tell me guys... What to do?... All my time with her wasted for her best friend in 1 night... (they both live in the same city tho), do you think she doesn't love me anymore?...