I'm really sorry to hear about your mom. When I lost mine, it just tore my heart out by the roots. Eventually the sharp pain receded and I was able to also remember the good times and be grateful for them. Let them warm me all over again. Still, the grieving process is very hard. It might help to read about some of the stages of grief and familiarize yourself with the grieving process. Allow yourself to cry. It really does serve as a catharsis. I used to take walks in private places and shout at the sky.
Losing your mom is bad enough, but to be left alone is it's special form of hell. In some way, she will never leave you though. She will always be in your heart and mind and you can still hug her presence to you. It's been 20 years since I lost mine, but I can still pull her up. I miss her. I always will. But she is still there in me as a good role model and a loving presence.
Your mom would not want you to be so unhappy. She would want you to reach out to people and go on. People do create their own families (out of pets, if nothing else) and there is no reason for you to be alone the rest of your life. I hope we can provide some comfort here as you go through this.