Hunger is indeed a sharp thorn when it comes without reason and without relief, and your weariness under it is not strange. There is nothing in hunger itself to invite contentment, and when necessity lays its stern hand upon a man, he feels its bite through his whole nature.
There are two hungers known to our frame, and it is well to consider which it is that troubles you. The one belongs to the body, and the other belongs to the soul, and both are under the Lord's eye.
For the body, perfect health lies in the right condition of spirit, soul and body together, and the Lord Himself is the health of our countenance. When the body is out of order, the face soon tells it, and the spirit is cast down. If this continual hunger is of the flesh, do not despise the means which Providence affords. As you would go to a physician for any other infirmity, so seek counsel for this also, and ask the Lord to bless the inquiry. He who walked among the sick and healed all manner of maladies is still the Great Physician, and He often works by the skill He has given to men, though all health at last comes from His hand.
Yet there is a hunger which no bread can fill. I have seen men devoured with hunger in the midst of plenty, unrestful though surrounded with comforts, lolling in abundance and yet envying the poor man's appetite. Their gold had become their strength, and their strength was bitten with hunger. It is a great blessing when food and appetite meet together, but it is a greater blessing still when the soul finds its proper meat. Some have meat but no appetite, and some have appetite but no meat, and neither is satisfied until the two are brought together in Christ.
You say you are hungry all the time and know not why. Take heed lest it be that the soul within is hungering and the body is made to echo it. The Lord has set within man a hunger not after wealth, nor after health, nor after the rewards of righteousness, but after righteousness itself. And this hunger is blessed, though it brings pain, for it is a paradox of grace that a man may be blessed while he hungers and thirsts. He cannot feed upon himself. He must have food from outside or he shall die. He says, I have tied a belt about myself to keep down the hunger, but I find no supply within. So he is driven to look without, to Him who is bread for the hungry.
Contentment is one of the flowers of heaven, and if we would have it, it must be cultivated. Remember that a man's contentment is in his mind, not in the extent of his possessions. Alexander with all the world at his feet still cried for another world to conquer. But he whose faith rests upon the sovereign goodness of God has peaceful contentment in his breast while tribulation lasts as well as when it has closed. He learns in whatsoever state he is, therewith to be content.
Therefore I would point you to the one fitness which is needed for eating, which is an appetite. You have it. Lay to, then, by holy faith. Receive Christ into yourself and He will be sweet indeed to you. Even bitter things become sweet to the hungry man, and to those who hunger after Christ, repentance itself becomes one of the daintiest of divine graces. Blessed are they which do hunger and thirst after righteousness, for they shall be filled. And this is the wonder, that when they are filled they still hunger, and when they hunger they are still blessed, for Christ satisfies and yet enlarges desire, so that the soul cries more and more for Him.
May the Lord the Holy Spirit create in you that spiritual appetite which is half the battle, and then surely you shall have the meat to satisfy it. May He be the health of your countenance and your God, giving you inward peace which shall show itself outwardly, and teaching you that whether with much or little, in hunger or in fullness, your strength is in Him. Cast this continual hunger upon the Lord in prayer, asking Him to show you its root and to fill you with Himself, who alone satisfies all comers. To Him shall be glory forever.