Simple Sentences:
* The loneliness of the empty house was overwhelming.
* She fought back tears, battling the loneliness that gnawed at her heart.
* His loneliness was a constant companion.
More Complex Sentences:
* Despite the bustling city around her, she felt a crushing loneliness that only grew with each passing hour.
* His loneliness was a tangible thing, a weight that pressed down on him until he felt like he couldn't breathe.
* The loneliness of the long winter nights was a stark contrast to the joy and warmth of summer gatherings.
* The loneliness she felt after her husband's passing was a grief that wouldn't be easily overcome.
Figurative Language:
* Loneliness was a serpent coiling around her soul, constricting her with its icy grip.
* Her loneliness was a gaping hole within her, a void that nothing could fill.
You can also use loneliness in different parts of speech:
* Noun: The loneliness was unbearable.
* Adjective: She felt a lonely feeling, lost in the crowd.
* Adverb: She walked lonely down the street.
Remember to choose the best word and structure based on the specific meaning and context you want to convey.