i felt this way too when my mom passed. it was a good year before i felt that i wasn't in a "daze". a good 2 years before i could think of my mom and not tear up. it's been 6 years now, and when i think of her, i smile with good meemories. i still have moments when i'm sad thinking about what i'll miss without her by my side. and i use to hate it when people say the pain will past. there was a part of me that felt that if the pain past, then it meant that i was forgetting her. it was so odd to me that the world went on without her, and it has.
i felt isolated as well. and the hard part was to let people in, and it meant that i had to cry out to them. most people just don't know what to do... so they do nothing. it's really ackward. some people can deal with it, others can't.
i know it sucks right now, and it feels like your heart will never heal. but time does help. you are not alone, and i wish you the best.
my aunt told me because i took good care of my mom when she was dying, that i would be looked after for the rest of my life. that i would never be alone and my mom would always watch after me. i know its corny, but it's true.
hope this helps.