Best Friend is now Dating MY Crush!

This is going to be a long question because I need to give the background story so everyone can fully understand this situation.

Back in maybe October or November my friend (let's call her Jen) and I had tried to hook up our other friend (we'll call her Taylor) with this guy they both knew (he'll be Lucas). So after Jen and I tried really hard we both gave up because Taylor and Lucas were both disgusted at the thought of being with each other and Taylor was adamant in letting us know that Lucas was far from her type. So in the process of trying to get them together, I got to know Lucas better and discovered that I was developing a small crush on him. So I told Taylor and she told me to go for it after I checked and double checked and then rechecked that she absolutely did not want him. She always said no. So I started talking to Lucas more and with Taylor's help we became friends. I put some serious effort into this guy, I would drag Taylor and Jen to his outdoor track meets and sit in the freezing cold because I would promise him that I would go cheer him on. I even gave him congratulatory hugs if he won a race (even when he was all gross and sweaty). However a few months down the line Taylor starts making little comments like how she thought Lucas was getting cuter, and she kept asking me if I was still into him...I always said yes. So she offered to help me speed things up with him, so I thought. I told Lucas that I was attracted to him and that I liked him, and he gave me that nice little sugarcoated rejection...you know the "You're really cute, I just don't want a girlfriend" Ouch. So I confided in Taylor and Jen about my crappy relationship history. I even told them how a few years ago another really close friend I had intentionally went after and dated the guy I told her I was into and how much that kind of betrayal hurt me and how I hoped it would never happen to me again. So about a month goes by and summer's coming up and I start to see Lucas and Taylor getting extremely close. They'd flirt and hug for a little too long, and I was saw him with his arms around her cuddling but they both moved away when they saw me coming. I knew something sketchy was going on but I knew my friend and figured she wouldn't do something like that to me, not after I told her how much it hurt the first time around. So summer vacation came and in late June I went to Bahamas with my family for two weeks and I talked to Lucas a few times and was really excited to hang out with him when I got back. When I got home, Taylor texted me saying she had to tell me something. She then proceeded to tell me how she and Lucas are now dating, exclusively, and wanted to know if I was OK with that. I was devastated and hurt and I felt betrayed. I told her that I wasn't OK with the relationship at all but I didn't want to stand in the way of her happiness. I cried for a week but I don't know what to do, I don't want anything to do with their relationship, how should I deal?
Updates
+1 y
I know he'll be around our close group of friends now more since they're together but I don't think I can handle seeing them together. I feel like a fool because everyone knew but me and I gushed about him all the time...no one thought to tell me.
Best Friend is now Dating MY Crush!
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