I must say, No - I have not gone through what you are currently experiencing - but you were a blessing to your mother. You "honored" your mother during her years here on earth - you obeyed Our Heavenly Father Commandment in respects to honoring our parents. You were a very beautiful daughter to your mother.
What do you do now? Cherish all of the beautiful memories of your mother and live your life now. Enjoy to the fullest your 2 daughters. I know, there were so many sacrifices you made in your life in order to care for your mother. Take time in getting to know who you are and to really get to know your children.
If you believe in God - Please take the time to get to know your Heavenly Father. I do hope you get to meet someone at this site who may have experienced the same as you.