You have been bamboozled sir. You say they treat you like a friend, but that is your attachment to them talking. Your emotions are blinding you from seeing the truth. You will likely not realize this until that day when you can move on, which may be month from now, but this is what is going to happen. You are going to think to yourself when you are healed "damn what the hell was I thinking wasting time with her". If you can realize that faster, your transition will be so much easier, you would save much time in which you could have been very productive, and find an actual love of your life, and you would not suffer the permanent effects of heart break like being negative. Your friend? Pssh, my friends and I joke around and say this but, its kinda true, bros over "hoes". No true friend (especially if you two were friends before her) would let a girl get in the way of your friendship. He is definitely not a friend if he chose to date your ex (which by itself may be fine), and talk to you about how good she is and stuff. That is simply torture, I think I'd probably enjoy breaking his ribs or something if he wasn't even considerate enough to shut up. The girl... well she obviously knows how to play mind games, they are the worst.
