He renews you
A long, hard stretch drains you, and at some point you are tired, worn down by carrying it. Scripture promises something specific to the worn out: renewed strength. Not strength you generate by trying harder, but strength God supplies to the ones who keep turning to Him. It tends to come without fanfare, enough for the next step, then enough for the one after. If your tank is empty, stop trying to refill it yourself. Bring your tiredness to God and ask Him to renew you. He does His best work in people who have run out of their own strength and turned to His.
But they that wait for Jehovah shall renew their strength; they shall mount up with wings as eagles; they shall run, and not be weary.
Isaiah 40:31 · ASVIsaiah promises that those who wait on Jehovah renew their strength and rise like eagles. Strength is renewed in the waiting itself, not only after it ends.
Wherefore we faint not; but though our outward man is decaying, yet our inward man is renewed day by day.
2 Corinthians 4:16 · ASVPaul admits the outer self wears down, but says the inner self is renewed day by day. Even as life takes its toll, an inward renewal is described as ongoing and daily.
In the day that I called thou answeredst me, thou didst encourage me with strength in my soul.
Psalm 138:3 · ASVDavid recalls that when he called, God answered by strengthening his soul. The help came as inner strength, exactly when he asked for it.
He restoreth my soul: he guideth me in the paths of righteousness for his name's sake.
Psalm 23:3 · ASVThe Shepherd restores the soul and leads in right paths for His name's sake. Restoration is presented as the Shepherd's own work, done repeatedly.