I am so sorry for your loss. To have someone you love die, is the most horrible feeling. And then to go suddenly, when it had been expected that he was going to be getting better, it is so hard to accept.
Once you get past the grieving, and accept that he is truly gone, I hope, in time, you will enjoy each day of remembering what a great father you had. To allow his love to be all embracing for you. That in time, his memory will give you a serge of joy and happiness... that you were truly loved by a wonderful man. Wouldn't that have made him happy? That his love for you made you a better, stronger person? Are you able to show that kind of wonderful personality your dad had to others? To be as loving and thoughtful as him? A little bit? If so, then it would be as if he were still by your side, helping you, help others.
So sorry what you and your mom have gone through and are going through still. It is so painful having to get rid of possessions that hold so many happy memories. Do you absolutely need to sell the house?
Hugs from a concerned internet friend.