I couldn't even think about losing both parents right now, so do feel for you and have a good idea of what you're experiencing.
We all want deceased family and friends to come back. There hasn't been an hour in the day since I lost someone recently, that I wish they were back, and it fucking hurts - I understand completely, but sadly we have to realize there's nothing we can do about things. The waiting of acceptance is the hardest part.
As others have said, they wouldn't have been the only one to look out for you or offer love. You will hopefully have other living relatives you can take comfort in, so why not pay them a visit or spend some time with them ? That's what I plan to do over the difficult end of year period - spend time with others who care. They won't bring back the people i've lost, but we'll support each other and make things better. Say it every time, but I hope things get better in your circumstances.