“Will Jehovah cast us off forever? […]
Or has his anger caused his mercy to cease?”

~Psalm 77:7,9

These questions are meant to be rhetorical but God’s word clearly gives us the answer:
No.
Jehovah God is not cold-hearted and wrathful to the point of being unforgiving.
It is normal to be haunted by a guilty conscience and wonder if God will forgive us when we have failed Him.
But He has provided the means to forgiveness through the sacrifice of His son (1 Thess. 1:10).

God promises to not stay resentful toward sinners who return to Him (Jer. 3:12).

He even goes beyond that and offers to comfort us (Is. 12:1).

So if our faith begins to falter because we fear Jehovah has cast us aside, let us remember all that He has done for us in the past and patiently treasure it as evidence of His unrelenting love (Ps. 77:11).