it does to him:

The first misfortune of my life occurred—an omen, as it were, of my future misery.

He then describes a process of mourning that includes a first wave of sadness, the bitter grief that occurs as time goes on, and the acceptance that eventually comes. Victor finally turns to preparing to leave for the university at Ingolstadt, a departure that had been delayed by his mother's death. By this point, he can dwell philosophically on being grateful to be alive, a sentiment that will change after he builds his creature.

Ironically, in chapter 1, Victor speaks of the value of his parents' nurturance as the basis of his happy life, a model he will not follow when he brings his own creation to life:

I was their plaything and their idol, and something better—their child, the innocent and helpless creature bestowed on them by Heaven, whom to bring up to good, and whose future lot it was in their hands to direct to happiness or misery, according as they fulfilled their duties towards me. With this deep consciousness of what they owed towards the being to which they had given life...

Frankenstein copes with his mother's death in part by absorbing himself in his studies at the university, becoming obsessed with creating human life from inanimate body parts. When he does bring his creature to life, he flees it in horror, but then has a dream in which he thinks he sees Elizabeth. However, when he kisses her, she has changed into the corpse of his mother, foreshadowing Elizabeth's death and suggesting that his mother's death still haunts Victor.

Six years later, Victor will return home, see his mother's portrait and feel it is so dignified it "hardly permitted the sentiment of pity." His tears are for the miniature of William below it.

To be blunt, Frankenstein doesn't truly cope with his mother's death. In the immediate aftermath of her death, Victor works to push past his feelings of grief, noting, "we had still duties which we ought to perform" (Chapter 3). Thematically, however, it is no coincidence that Frankenstein begins his studies at Ingolstadt just after losing his mother, since it is at Ingolstadt that he learns how to turn his childhood interest in alchemy toward a more scientific method of bringing the dead to life. His passionate denunciation of the evils of mortality suggests that he has not come to terms with his mother's death ("I saw how the fine form of man was degraded and wasted...I saw how the worm inherited the wonders of the eye and brain"), as does his tendency to see Elizabeth as a stand-in for his mother (Chapter 4). In fact, Victor conflates the two women in a nightmare that follows his animation of the monster: "I thought I saw Elizabeth, in the bloom of health, walking in the streets of Ingolstadt. Delighted and surprised, I embraced her, but as I imprinted the first kiss on her lips, they became livid with the hue of death; her features appeared to change, and I thought that I held the corpse of my dead mother in my arms; a shroud enveloped her form, and I saw the grave-worms crawling in the folds of the flannel" (Chapter 5). The fact that Frankenstein's disappointment in the monster immediately calls to mind images of his mother and Elizabeth dying strongly suggests the role that grief and fear played in driving Frankenstein's experiments.On a related note, it's worth pointing out that Mary Shelley wrote Frankenstein shortly after her first pregnancy ended in the death of her newborn child. For that reason, many critics have suggested that Frankenstein's troubled relationship with the creature he brings to life may actually be a statement on motherhood (see here, for instance). If we find that argument persuasive, Frankenstein's unresolved feelings about his own mother assume even more significance.

Victor states in the novel that he was his parents' "idol," although his mother had always longed for a daughter. As such, he is devastated by her death. Victor describes this devastation, however, not as something unique to himself, but as something that can be understood by anyone who has had a loved one die—"the sorrow which all have felt, and much feel." Appropriately, Victor's reaction to her death is not immoderate; he comments that "the time at length arrives when grief is rather an indulgence than a necessity," and indicates that after this time had passed, he was able to dedicate himself again to the "duties which we ought to perform." Very rationally, indeed, Victor advises that those who have lost loved ones should "learn to think ourselves fortunate" still to be alive ourselves.

When the grief was fresh, however, Victor felt "alarmed" by it, and coped by staying close to those who remained with him, especially Elizabeth. It is suggested that Victor clung somewhat to Elizabeth during this time, using her (to an extent) as a replacement for his mother and taking succour from her "sweet smiles."

Not surprisingly given the closeness of the Frankenstein family, the death of Victor's mother was a source of great sadness.  As Victor himself described the evolution of his emotions, grief was soon followed by bitterness, which was in turn followed by a resurgent need to get on with his life.  For Victor, that meant beginning his journey to Ingolstadt to commence his studies.  

Victor's sadness resulting from the death of his mother, however, would never entirely go away.  Her death, in fact, would prove the first in a long line of tragic events with which Victor would have to cope.  In this, he was comforted somewhat by his cousin, Elizabeth, who lived with the family and who, it was understood, would eventually marry Victor.  The death of his mother could also be said to have contributed to the extreme determination with which he pursued his research into the possibility of reanimating dead tissue.

My mother's tender caresses and my father's smile of benevolent pleasure while regarding me are my first recollections. I was their plaything and their idol, and something better—their child, the innocent and helpless creature bestowed on them by heaven,...