Why won’t they give me a misdemeanor with injury instead of a felony for a first time offense?

I got a DUI and somebody got injured. I've never been in trouble in my life and never been arrested in my life ever. This will be my first offense. I went to court and I've been going to court for the last 7 months now. They have changed the DA 3 times. They keep pushing back the court dates because the new District attorney needs to review the case. I am not saying that I didn't make a mistake as man I admit yes I made the mistake. I hit the curb and my car swerved and hit her. But because I was driving under the influence, they blamed that. The lady lied and said she has a broken bones in her back. I knew that was a lie. But they tried to give me a GBI enhancement but once they got the medical records back, they found out there was no GBI. No broken bones according to her doctor. I knew that because the impact was not hard enough to cause great bodily injury. I just want to know why they won’t give me a misdemeanor with injury. My PD keeps coming to me with offers and deals which doesn’t make sense. I’m not educated in the law department but I’m not incompetent either I have done my research. She won’t ask for a misdemeanor. I feel she’s working with the DA. Why are they trying to give me a felony and it's my first time. I have no criminal history at all and I just want to go and do my classes so I can get back to my livelihood. I have to take care of my family. I work every day, been at my job for two and a half years. I don't get in trouble. I just made a mistake. Should I ask for a speedy trial? I am 25 years old and I really need some closure and advice.