I really don’t have anything to add to this, but I’d like to give a bit of a personal reflection on the nature of Purgatory, given that you are still struggling with it. I believe everything I’ve written here is in keeping with Church teaching; if someone sees something that isn’t, please let me know. ^^
Please remember that we know very little about Purgatory. We know that it is a necessity, nothing impure can enter Heaven, and at death we may still have lingering sins, or the consequences of sins, that need to be accounted for. We do not know if this will take any “time” at all, or if it will be instantaneous upon our death. We also don’t know how this purification takes place; Christ alludes to purification through flames several times throughout the Gospels, so that is how a lot of Catholics envision it. (That is also how St. Faustina described it from her private revelation, which is not binding, but very… well, frankly it’s frightening to read, but very impactful.)
We also do not know what kind of existence Purgatory is. We know it’s a spiritual reality, but we don’t know if it’s something analogous to Heaven and Hell (a spiritual “place”). I believe Pope Emeritus Benedict XVI described it as the piercing gaze of Christ, in which we cannot hide from the effects our sins have had on ourselves and on others. To put it simply, we won’t know this side of Heaven what Purgatory is like. Pope Emeritus Benedict XVI may be completely wrong, and it may be a place of purification through pure flames, though lesser in degree than the eternal fires of the damned; or he could be completely right, and when we die we will be met with the unfiltered gaze of Christ himself, with our consciences laid bare before us, unclouded for the first time…
When you think about Purgatory, don’t think about it as one of three options; think of it as a connecting stop, in which we are purified and truly made Holy in God’s sight; not by some masking of our flawed human nature, but rather through the complete repair of our broken human state. In Purgatory, we are made fully human, the flaws sin has created are truly removed, and we are returned to the state of perfection God envisioned for us in the Garden. From Purgatory, once we are made perfect, we enter Heaven and spend eternity with our Lord, fully human (spiritually at first, and then physically after the resurrection) for the first time!