All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
It is not permissible for you to lash out at your mother, even if it is motivated by your concern for her interests, and it is not permissible for you to speak to her in a harsh manner. The mother's right on her child is great, especially when she is old and weak.
Allah says (what means): {…say not to them [so much as], “uff,” and do not repel them but speak to them a noble word. And lower to them the wing of humility out of mercy and say: My Lord, have mercy upon them as they brought me up [when I was] small.} [Quran 17: 23-24]
Hence, you have to repent to Allah for lashing out at your mother and mistreating her and be keen on being kind to her by doing what is in her interest without lashing out at her or being aggressive with her, but in a kind and polite manner. Do not succumb to anger and impatience.
You should know that being kind and dutiful to your mother is one of the best and most beloved deeds to Allah, and it is one of the reasons for success and happiness in this worldly life and the Hereafter. So strive, and seek Allah’s help to be patient and kind to your mother. It is by training yourself to do so that you will acquire these qualities.
Abu Ad-Dardaa’, may Allah be pleased with him, reported that the Prophet, sallallahu ‘alayhi wa sallam, said, “Knowledge is acquired through learning, and clemency is acquired through practice; whoever sincerely seeks goodness will be granted it, and whoever sincerely avoids evil will be protected from it...” [At-Tabaraani and Al-Bayhaqi]
For more benefit, please refer to fatwas 86681 and 341224.
Allah knows best.