We all have at one point or another beat ourselves up (and unfortunately also beaten up those near to us) through unrealistic fantasies. But we do not see that an idea like as, "there automatically exists that one soul somewhere perfectly matched to me", is but an illusion which actually fails to prove true under scrutiny.
Truth is what will set you free and that means you are going to have to come to understand certain things.
(1) You are going to have to learn why it is a fantasy that there automatically exists that one perfect soul mate for you. And the short answer for that is that God is the only one who is supposed to occupy that space in your life. You must see and believe that he is your most important relationship in life and that if all other relationships in life betrayed you, your relationship with him is enough to sustain you.
Any other relationship you have the privilege of enjoying in this life requires flexibility and conformity on the part of both parties because our spirits cannot be perfectly in tune until both parties are synchronized by each independently being in tune with God's spirit. God has to be number one in both of your lives.
Now, you might imagine that there is another partner out there somewhere who is already in tune with God and is right for you. But you ought to know there is something wrong with that idea as if that other person is in tune to God's spirit then they would never see their self as right for you who already exist in a vow to be faithful to one other human in your life above all other humans. They would see that the relationship you already have is one that glorifies God by your faithfulness to it, as that relationship is a figure of your loyalty to God.
We must be realistic and accept that all relationships take work on the part of both parties, even when it comes to your relationship with your children. And God teaches us the way of truth (true knowledge, as opposed to illusions) which has the only hope and power to set us free from whatever our situation is. Not by abandoning our situation! By learning more fully to use the knowledge which is true and unselfish love and treasuring that knowledge above all other knowledge as it is what secures us to God himself.
(2) And so with all of that said, we need now to cast away the distraction of looking for the solution outside the relationship (perhaps having even to cast away thoughts that entertain an idea that the arms of another human await) and focus on our relationship with God and learning from him to have that truth of knowledge which will bring us to be as Paul described:
2 Corinthians 12:10 "Therefore I take pleasure in infirmities, in reproaches, in necessities, in persecutions, in distresses for Christ's sake: for when I am weak, then am I strong."
2 Corinthians 13:4 "For though he was crucified through weakness, yet he liveth by the power of God. For we also are weak in him, but we shall live with him by the power of God toward you."
Are we supposed to live that way towards strangers and not even more so towards our own spouse and children?
Ponder the Psalms and the proverbs and seek to make each thought understood and a part of your heart.
I will give you only one to start with. Perhaps others here might relate more of these thoughts to you.
Frustrated expectations are the cause of much of the heart's bending down (falling to sadness, exasperation, and like temperaments).
Proverbs 13:12 "Hope deferred maketh the heart sick: but when the desire cometh, it is a tree of life." (KJV)
Proverbs 13:12 "Hope deferred makes the heart sick, But when longing is fulfilled, it is a tree of life." (World English Bible)
That is what is happening to you.
But it is happening because your longings are unrealistic. You hope or wish for an idea that is mere fantasy and you must come to accept that it is illusion and fantasy or you will keep wishing for it and your heart will keep feeling sickened because of that wish.
Instead of seeking to find a way out of your misery, seek to transform yourself by the truth of God which is your only real hope of freedom from the heaviness your heart now bears.