im so sorry about whats happend...
i feel for you seriously i have lost two of my grandparents within a year and it hurts...
I will give you many spells and also cast some for you. I don't normally do it but i really think you deserve this. So i will cast a higher magick love spell. Also hear is a few spells to help you out in general.
To get back a loved one.
Stick a needle through the wick of a candle. Light it then concentrate, clear your mind and chant:
???Needle in the flame,
Needle of fire,
Pierce his thoughts.
Make him writhe, agonize,
Till his heart turns back to me."
It sounds like black magic but its not i have tested it.
If thats enough just now then good luck, if you want more then just feel free to ask.