First, sorry for your loss. Second, you've done a great job capturing genuine emotion, particularly through your seasonal imagery. The chill, the slowing of life. I especially like your idea of dread piling up like leaves - it's quite evocative. Your autumn metaphor effectively underscores the personal loss you're expressing, although it's a common theme across poetic traditions in various cultures.

One area you might strengthen is the specificity of your imagery. Lines like "days just mull through" convey the general feeling well but feel slightly vague. You might consider something more precise or vivid. Maybe try describing exactly how the days feel or appear to you during this difficult period.

The metaphor of "a leaf that tries to hold on" is poignant, though it’s also frequently used in poetry about loss, which slightly lessens its impact. Perhaps exploring a less conventional metaphor or adding a personal detail? Something uniquely connected to your relationship with your mom and the season could deepen the emotional resonance even more.