Then as he (Elijah) lay and slept under a broom tree, suddenly an angel touched him, and said to him, ‘Arise and eat. – 1 Kings 19:5 (NKJV).
1 Kings 19:1-8
There is nothing as refreshing as the times when you feel a personal touch from God in the midst of tiredness and discouragement.
You should learn to rest in God when all looks bleak and hopeless. You should allow Him to feed you with the meal of the Word (water), because that is the only cure for discouragement.
Above all, God also cares for your physical condition of lack; e.g tiredness, lack, illness, etc, and so He gives bread for your nourishment, which is your daily divine provision.
Philippians 4:19, John 6:1-13
Ask and receive sustenance from God, that will keep your spirit, soul and body always refreshed.