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She is probably feeling anxiety .Anxiety can cause gastritis
so burping , tremors , heat pain , rapid heart beat.She might be having frequent urination
due to anxiety or an Urinary infection.She has to attend her Physician and get evaluated.
Anxiety can present as a chest pain
with difficulty in breathing which typically appears like heart attack
.Though it is not to be neglected , it should be evaluated first.
Hope my answer is useful to you and all