I think I just lost my best Friends. Am I Stupid?

I am in the Marine Corps. and picked up the rank of Corporal in January. With becoming an NCO you have to leave your friends and peers behind. I however never felt like an NCO. I met one of my best friends in Korea.. a Marine too, but a Lance Corporal.. lower than I. I got really close to him and my other best friend.. Nothing could stop us from being together and we had plans for the future and never leaving each other. However, about a month ago, my command has been riding us to seperate and stop seeing each other. We work in the same work space, but as I said before, I dont really feel like I deserve, or am supposed to be a Leader. The command finally got to me and I stopped hanging around with them. This lasted only one day because it was so hard to let them go. I started talking to them again but the command got really into it and I just stopped last Thursday. It has been three days now and I am losing my mind. I hate doing anything and cant stand to leave my room on account of I might see them again. I wrote them a letter yesterday and gave it to them. She then came to me and told me to chose my own friends and not let other people tell me what to do, calling me a ***** and saying **** you to my face. I then later today got a hurtful letter that made me think a lot.. so I then wrote one back saying I was ending everything we ever had for good. This was ten minutes ago and I dont think they read it yet. I just slid it under the door. Did I **** up??