I am so sorry you do not get support from your siblings. God sees everything and you will be blessed for your loving efforts. I am so happy you get to make your mom feel good and I know that makes your heart glad. Although you do not have friends you can gain encouragement by reading some of the post from other discussion boards... Your faith will heal in time...( 1Thess 5:11)
Your memories will always be there and I know you have good memories... The grief will be there (Romans 9:2) Everyone experiences grief in different ways . What has help me is staying close to family & friends that are good association (positive). I mean positive and up building influences in your life. I also have a strong tie with my religious community. Some have seen a therapist or psychiatrist. It's nothing wrong with that. It is nothing wrong with crying and shedding tears....My heart goes out to you and you will find so many people with similar experiences on this website.
Being a caregiver can be very hard... I do not know what your circumstances are but if you have siblings, I hope they are sharing the load. If it's more that you can handle please ask for assistance.
We love you Gloria and we will endure.. God hears your cries