hard to bear

• unbearableImpossible to endure
• painfulCausing hurt or ache
• agonizingIntensely painful or distressing
• crushingOverwhelming in intensity
• overwhelmingIntensely excessive in force

suffocating · excruciating · torment · burden · weight · heavy · grief · anguish · heartache · strain · exhausting · relentless · grueling · intolerable · unendurable · oppressive · stifling · misery