In Mary Shelley's Frankenstein, the creature was more miserable than Victor, because he was brought into the world alone, and he never had any being to share any strong compassion with.
Victor was miserable because he lost all that he ever had and ever loved, but at least he had those memories and experiences from his younger days to hold on to. Throughout the book, he had family members and friends that all loved and cared for him. He never felt hate from any of them, and he never felt hate towards any of them either. His love for Elizabeth was especially like a driving force or motivation when times were bleak during the periods of his experiments. And, at the end of the book, he said that, "wherever I am, the soothing voice of my Elizabeth, and the conversation of Clerval, will be ever whispered in my ear" (p. 157). Even after his fiancée and his best friend had passed, he still connected with them, and he still felt their love. Also, while he did lead a miserable life after the deaths of his loved ones, he was at fault. Victor brought on most of his and the creature's misery through his own ignorance and blinded determination. The creature's solitary life was an effect of Victor's shortsightedness, and the creature could do nothing to preven this misery.
The creature knew that there were such things as love and kindness from his observations of the peasant family, but he never got to receive those feelings himself. He tried to give kindness to others, like when he gave firewood to the peasants and when he saved the little girl from drowning, but his only "rewards" for such acts of kindness were to be shunned and shot at. The creature's violent demeanor was a direct result of the poor treatment that he experienced from humans. He felt horrible for his actions, especially when he shot Clerval. He told Walton, "My heart was fashioned to be susceptible of love and sympathy...