I can't live with out my mum

My mum passed away on the 23rd August 2021, due to bowel cancer she had been going to the drs for 5 years, but January 2021 they decided to send her for the camera it wasn't good news. She fought a hard battle right to the end I miss her so much.  In between this my sister was diagnosed with stage one bowel cancer my mum never found out.  I took my sister to every appointment, whilst taking food in for my mum to give her the food she enjoyed.  My sister is in the clear now, I also been helping my dad.  But cannot come to terms that my mum is no longer here, I feel she is still up the road in hospital. I just feel so worthless now with out her here, I am under the care of the community mental health team and have been for 2 years now. I am just so tired of feeling this way. Always down in the dumps trying to put on a brave face. Any advice would be greatly appreciated. Kind regards Bobby