You say you feel overwhelmed with guilt and a sense of unworthiness.
Well, you cannot be too aware of the inward and inbred evils you complain of, but you may be (indeed you are) improperly controlled and affected by them.
You say it is hard to understand how a holy God could accept such an awful person as yourself.
You, then, not only express a low opinion of yourself (which is right!) but also too low an opinion of the person, work, and promises of the Redeemer, which is wrong. . . You complain about sin, but when we examine your complaints, they are so full of self-righteousness, unbelief, pride, and impatience that they are little better than the worst evils you complain of!—Works of John Newton, vol. 6, p. 185.
Hat tip: How an Inferiority Complex Can Be a Form of Pride – Justin Taylor: