Lost my dad and then lost what feels like everything else ...

I lost my dad suddenly, 6 months ago just before I was gonna come home and live with my parents again. I couldn't say I love you or thank you, or give him a hug one more time and it kills me. Just after I lost my dad I lost the relationship with the person I thought I'd be with forever and with that I lost the person I was. Each day I just go about doing what I have to do and I just feel so lost and I have no bearings anymore. It feels like my friends have forgotten about me and just carry on with their own lives. I feel as if I've lost my whole world. Im just writing this because I've never felt this empty or lost before and I have no idea on how to move forward except for taking it day by day as everyone says... It feels like there is a void inside of me and I dont know how to live with it.