This is so messed up......

So before I start getting into the issue I'm going to say that my bf is now my Fiance, he proposed to me on the 21st and It was by far the happiest day of my life. I was so happy and excited to be planning a wedding with the love of my life. He was planning to propose for months and it was so special. But to make a long, depressing story short... Now that I am engaged to be married, so his my fiances little brother and his gf.... So now that she has a ring that someone just had laying around, they are talking about her wedding more than my very real wedding.... An engagement is something I was not planning on sharing with a girl I barley know... When my fiances family comes to me about a wedding, they also talk about hers as if we are the same person.. I feel like my engagement and wedding has been taken from me and I have never been so devistated. He didn't propose to her.... I got proposed to in the most special way by the love of my life who planned it for months and now I feel like it means nothing.. Idk what to do.. They are both 18 and have been together for like three months and now I feel like everyone is taking their engagement more seriously just because she is very pushy and expects everyone to talk about her while they are talking about my wedding and my relationship. Anyways.. I feel like when I mention how I feel about this no one understands and think I'm overreacting. But I feel like they stole my engagement, my wedding and my happiness.. I'm sure someone on here will understand. And the picture is of my beautiful ring. Its real and it has so much meaning since it was his moms ring.. Her ring is something his aunt gave to her that came out of a storage locker.. Ugh