lost my Mum to lymphona

I lost my Mum last June 25th 2019 to Lymphona non hodgkins. 
I  do feel angry as the local GP as they just kept saying for 6 months to my Mum (2018) she had bad sciatica, finally after she started collapsing i called this doctor and  managed to get her an MRI on Xmas eve 2018, then we had the bad news that day she had a large tunour on her spine, after 5 months of chemo she was told she had 3 weeks to live....   l am still struggling to come to terms with all that has happened so fast....    I find it unbearable at times, I cry all the time, just miss her so terribly.  She was my best friend and mum.  Miss her so much,    Will it ever get better?