One is the permanent loss of any possibility of receiving the parental love that every child deserves.
The second is the actual human being that was your parent.
Separate the two.
Grieving the first does not require you to grieve the second.
And remember that there are no "should"s in grief: we might grieve over something that has no logic behind it, and we might not grieve when someone else thinks we should.
Ignore all of that.
Focus on what your grief is telling you is important, and use any future opportunity for growth to grow in that direction.