Baby upset??

I need help! Recently ive been introducing food to my almost 6m old. Ive been following all the rules 👌 in short, im just worried and i suffer from anxiety. I think its the single grain oatmeal ( she ebf) gives her gas maybe?? When i hold her to nurse she bucks and arches her back and pulls away and crys like i dont know what! Like shes severely uncomfortable 😢 her dirty diapers haven't really been noticeably different. Im fully aware of phoning the doctor but i wanted to reach out and find out if others have had this happen?