I hate this dam diet

How am I supposed to live my life and actually do social things like go to a birthday party ? I have no clue what's going to be there to eat. I'm staving because I decided to eat lunch right before I leave and I took my snack with me.I'm screwed if they have pizza and stuff plus it won't even be time for my dinner do I'm just supposed to sit there when other ppl start eating ? I hate this. Ppl will ask why aren't you eating. I don't feel like telling ppl I have gestational diabetes it's something I feel ashamed of 😢