I can’t get my sugar under control. Is it too late?

I was diagnosed at 34 weeks, I’m now right at 36 weeks. According to my test results my doctors office has known since 28 weeks. They’ve told me just to check my sugar 4 times a day and to watch what I’m eating. My fasting numbers are always between 80-96 while my 2 hour after meal numbers are always 120-160. I have cut way down on soda and other sugary drinks, I’ve cut back on carbs and started counting them and I’ve stopped eating out as much. I’ve even tried to be active but at this point in pregnancy it’s very difficult. I feel like a failure because I can’t get my numbers down! My family history is a long line of diabetics who never have low numbers. My dads normal is mid 200s so I feel like I’ve just inherited high blood sugar. I feel like I’m failing myself and my son because my numbers refuse to be in the target range no matter what I do. I’m worried what my doctors are going to say and I’m worried about my sons health. I’m so terrified I’m going to kill my son because it hasn’t been under control and I’m having a hard time controlling it. Any other moms have high numbers no matter what you do? I just feel so alone in this because my mom keeps telling me those numbers aren’t bad because she’s seen so much higher working in the medical field but I know they’re not what they need to be 😔