Oh Yorkiemom, I really feel for you.
My Dad died 2.5yrs ago (suddenly) and after 5 months I was still a wreck. I think the best advice I can give is to be gentle with yourself. Nobody can prepare you for losing a parent, whether they are ill or not.
Grief is a strange thing that comes and goes. Even now, I still have days when I think - Jesus I miss Dad, wish I could talk to him, hold his hand...
It took me months and months to accept and grasp that my Dad was dead. I could accept theoretically that the person (ie Joe Bloggs) was gone, but couldn't seem to link that person to my Dad and that he was gone too.
I second everything NormaJeanBaker said... you never get over the loss. It took me about eighteen months to stop feeling bitter (once it came) but everyone is different. I don't know whether you have seen this poem before, but I always find it an immense comfort when I'm having a blue day -
Miss Me, But Let Me Go
When I come to the end of the road
And the sun has set for me,
I want no rites in a gloom filled room
Why cry for a soul set free!
Miss me a little, but not for long,
And not with your head bowed low.
Remember the love we once shared,
Miss me, but let me go!
For this a journey we all must take,
And each must go alone;
It's all a part of the master's plan
A step on the road to home.
When you are lonely and sick of heart
Go to the friends we know,
And bury your sorrows in doing good deeds,
Miss me, but let me go.
Robyn Rancman
Remember that it isn't weakness to cry, to grieve - it is always better to let it out than to crumble inside. You have been through a horrible time and 5 months is nothing to recover from it. It will take time, but it will get easier.