Secretly dating my best friend behind my back?!

My guy best friend and I have been friends for 4 years same thing with my girl best friend. The guy I used to have a major crush on. I thought I was in love with him. But he did not feel the same way about me. After going through pain for 2 and a half years I decided it was time for a change. So I took a break and got over him with a support group online. I came back to our friendship with and open mind and no romantic feelings. A couple days after I rejoined him he tells me that he is in a relationship with my girl best friend which I was fine with. Then I asked him how long and he lied and said he didn't know. Eventually I got him to tell me that they had been dating for 6 months! I had sent him nudes and he sent me dick pics...I told him that I loved him and he just dragged it out and he was dating my back stabbing bff the whole time. She isnt innocent either, she knew I had feelings for him. I'm so mad and sick to my stomach. Some support would be great and both my best friends are off the market rn so I would love it from you.