Domestic Violence Case- Thrown under the bus?

I was in a fight with my fiance alone in the car. She was really angry I asked to go together to a party where she thinks a girl was at. I was in the penger seat and she began punching me with the back of her fist. I slid away and grabbed the upper door handle with my right hand blocking her with my left. She started speeding and hitting the brakes. She took out her cell phone and said she was going to call this girl and call her a sl##. I told her she was scaring me and to chill. She then s hit me with her phone in the chest and arm. I threw her phone out the window and told her to let me out of the car. She started swirving and speeding again. She let go of the wheel and tried to choke me. I started to hit her off me and to let me out of the car. She locked up the brakes and swirved right into a parking lot. Holding on to the handle with my right hand my left arm swung up and my watch scd the side of her head. Once out of that car I got out. Next thing I know the cops call me on my cell and want to talk to me. They questioned me for 5 minutes asked why my neck was all red then arrested me for domestic violence and Felony 2 Aggravated Battery causing serious bodily harm. She went to the hospital and got a staple. After getting out of jail I contacted an retained an attorney. She didnt call 911 cause she didnt want to go to jail but neighbors did when she went overclean her cut. She gave statement to cops I hit her. She since has met with the State Attorney and VA and told them the real story and a not to prosecute waiver. That was about 2 weeks ago. My attorney is shocked and keeps telling me not to worry and it will either me dropped altogether or to a misdmeanor. Im facing 15 years so its a bit hard not to worry. Why is it taking so long before I hear if the charges were dropped.Please help if you have legal experience. Florida is a very PRO prosecute state and I feel they are trying to find anything to get me.