35y diabetic overweight

I have always wanted children. The drs told me when i was16 that i would never have them . I have pcos and now i have diabetes ( for 10 years now) i weigh 297 lbs and im almost 36. We got pregnant!!! The overwhelming joy was the 1st thing i felt ... now i am so scared . What if something happens... what ifs are taking control of my thoughts. I am high risk ( 3 strikes aganist me ) what can i do to ensure i have a healthy baby ? I have been constantly exhausted and nauseous. How do i keep my diabetes under control ? What can i eat that is better for me and the baby ? ... I am so ready to have this baby and i thank God for allowing me to conceive.