Proverbs 24:16
For a righteous man falls seven times, and rises again;
but the wicked are overthrown by calamity.
In the book of Samuel we read about two very depressed men who faced endless struggles. One was named Saul and the other David. When Saul faced a problem, his first instinct was to look to himself as the answer. As a result, his depression deepened into paranoia and fits of violence. Eventually, he slid into full-fledged rebellion against God and even sank so low as to consult a medium (who gave him the bad news that there was no escaping God by that route). David, in contrast, always tended to turn to God in his many times of trial. That doesn’t mean he was sinless. Far from it. He was an adulterer and a murderer. But when he sinned he always went back to God and took whatever God wanted to give him (including, on several occasions, judgement). As a result, though he fell many times, he always rose again, whereas Saul was overthrown by his pride and rebellion and never came back. In all this, we see a sort of mystical foreshadow of the Christian life: The point is not so much that we sin (everybody does that), but our sticktoitiveness in returning to God no matter what. God has forgiven billions of sins. The only thing that could possibly prevent Him from forgiving yours would be the refusal to accept His forgiveness. So go ahead: ask forgiveness and rise again. If David did it, so can you.