not hungry?

I rarely have an appetite and I'm almost 16 weeks. I feel like I'm barely eating enough calories for the both of us. Last pregnancy I had already gained 10 pounds by now and couldn't get enough food. I forgot to eat breakfast today and felts shaky, hot and got horrible cramps that lasted 45 minutes straight. Anyone else experiencing loss of appetite? I'm anxieties about baby are getting to me 😞