Mom triggers old bitter memories that irritate you by her behaviour. The frustration is because she does not understand and modify her behaviour to suit yours. At times, it could be possible that you are subconsciously copying some authority figure in your surrounding who is getting irritated with your mom.
Try writing the following positive affirmation 21 times/day for a period of 3 months and experience a remarkable difference. I choose to be very patient.
Note : An appropriate and well designed affirmation has the power to dramatically change your life for the better.
If, however, a particular affirmation does not resonate with you, please consult your local therapist or online healer.