Grieving only child feels like a failure

DEAR HARRIETTE: My mom passed away this year suddenly and tragically. I am still in shock about it. I was her only child. All we had was each other, and that’s all I let her leave with. I never graduated from college or had a great career; I never bought her a house or helped her move out of the one she raised me in. I feel like I failed her, and I hate knowing that she is gone now and won’t ever see me do those things in the future. Where does motivation come from when you’re drowning in guilt and sorrow? Do the things I’m worried about even matter? — Lost Without Mom