Yes it would be torment for the souls in hell to be in Heaven, in God’s presence, which is why hell exists… because they can’t be with God due to their rejection of Him.
However they also realize that they were made for God so they suffer the knowledge of their loss… .they suffer greatly for this but without any repentance or love. In Purgatory however, the souls also suffer from not being with God but they love Him and their suffering has a lot of longing for Heaven. (and they have repented of all sin).
Here is what St Faustina said about hell, when God permitted her to see it:
One day, just as I had awakened, when I was putting myself in the presence of God, I was suddenly overwhelmed by despair. Complete darkness in the soul. I fought as best I could till noon…I fell to the ground, despair flooding my whole soul. I suffered terrible tortures in no way different to the torments of hell. (24)
One day, I saw two roads. One was broad, covered with sand and flowers, full of joy, music and all sorts of pleasures. People walked along it, dancing and enjoying themselves. They reached the end without realising it. And at the end of the raods there was a horrible precipice; that is the abyss of hell. The souls fell blindly into it; as they walked, so they fell. And their number was so great that it was impossible to count them. And I saw the other road, or rather, a path, for it was narrow and strewn with thorns and rocks; and the people who walked along it had tears in their eyes, and all kinds of suffering befell them. Some fell down upon the rocks, but stood up immediately and went on. At the end of the road there was a magnificent garden filled with all sorts of happiness, and all these souls entered there. At the very first instant they forgot all their sufferings. (153)
Sr. Faustina is ‘transported’ to Hell -
Today I was led by an Angel to the chasms of hell. It is a place of real torture; how awesomely large and extensive it is! The kinds of tortures I saw: the first torture that constitutes hell is the loss of God; the second is perpetual remorse of conscience; the third is that one’s condition will never change; the fourth is the fire that will penetrate the soul without destroying it - a terrible suffering, since it is a purely spiritual fire, …the fifth torture is continual darkness and a terrible suffocating smell, and, despite the darkness, the devils and the souls of the damned see each other and all the evil, both of others and their own; the sixth torture is the constant company of Satan; the seventh torture is horrible despair, hatred of God, vile words, curses and blasphemies. These are the tortures suffered by all the damned together, but that is not the end of the sufferings. There are special tortures destined for particular souls. These are the torments of the senses. Each soul undergoes terrible and indescribable sufferings, related to the manner in which it has sinned. There are caverns and pits of torture where one form of agony differs from another. I would have died at the very sight of these tortures if the omnipotence of God had not supported me. Let the sinner know that he will be tortured throughout all eternity, in those senses which he made use of to sin. I am writing this at the command of God, so that no soul may find an excuse by saying there is no hell, or that nobody has ever been there, and so no one can say what it is like.
I, Sister Faustina, by the order of God, have visited the abysses of hell so that I might tell souls about it and testify to its existence. I cannot speak about it now; but I have received a command from God to leave it in writing. The devils were full of hatred for me, but they had to obey me at the command of God. What I have written is but a pale shadow of the things I saw. But I noticed one thing: that most of the souls there are those who disbelieved that there is a hell. When I came to, I could hardly recover from the fright. How terribly souls suffer there! Consequently, I pray even more fervently for the covnersion of sinners. I incessantly plead God’s mercy upon them. O my Jesus, I would rather be in agony until the end of the world, amidst the greatest sufferings, than offend You by the least sin. (741)