I was in sheer/utter/total despair. / I was bereft of all hope. / Despair closed in on me.

我完全绝望了。

After his wife’s death, he seemed to give himself over to despair. / His wife’s death seemed to have left him in total despair.

他妻子死后，他似乎万念俱灰。

Small steps that are obtainable will keep you from falling into total despair and giving up on the relationship.

小步骤，可将随时向你陷入彻底的绝望和放弃的关系。

If you don't let me heal this time, I humbly pray: Please have me killed! I am in total despair, please acquit me of the torment, God …

假如此次再不让自己康复那么求求你请杀啦自己吧失望啦放过自己…