Diabetes gestional. I'm so sad and scareeed 😒😭

Hii, i had a miscarriage last year and 3 almost 4 months after i was pregnant again im almost 30 weeks prego and today i found out i have diabetes gestional, i eat well and exercise constantly so i dont know why this is happening, im really scared of everything I've readπŸ˜’πŸ˜” i dont want anything bad to happen to my little rainbow, im so afraid but trying to be possitive because im so close to meet my little one but feel sad because i dont want to lose her 😞 i dont know anything about it and i would like some advices please!! πŸ˜”