Help?

My baby's farts seem to be bothering her. She hasn't slept very well for about a day and a half. She whines as she's sleeping and cries a little before falling back to sleep. She passes gas, cries and then seems to be better. She is eating well, so far but isn't sleeping very good. She's not eating as much or it might just seem that way. She's 6 weeks. I changed her to sensitive tummy formula when she was about 3 weeks.