Praise be to Allah.
We ask Allah to heal you, grant you well being, and bless you with a righteous husband and righteous offspring.
What is meant by freezing ovarian tissue is taking tissue from the woman’s ovary and storing it for an unspecified length of time; it is preserved in liquid nitrogen so that it may be re-implanted later on.
This technology is used by those who want to produce offspring at a later age, as it is well known that the woman loses the ability to produce eggs as she grows older.
The ovary stores a large number of eggs in the outer membrane at a depth of one millimetre. After taking a biopsy of ovarian tissue and freezing it, it becomes possible to restore the frozen membrane to its place (in the ovary) by means of laparoscopic surgery when the woman makes a decision to get pregnant at any time. In other words, it is possible for the ovary to regain its original ability to produce viable eggs, as if it produced eggs at the age at which the biopsy was taken.
See (in Arabic):
With this procedure – in addition to its high cost, as you said – there is also a risk of preserved tissue samples getting mixed up or switched, whether that is done deliberately or by mistake, which may lead to mixing of lineages. There are some doctors who do not fear Allah; if they see that a woman is very keen to have a child, that may prompt them to tamper with the samples and switch them so that she will get what she wants of becoming pregnant and they will get what they want of wealth and fame. For this reason the scholars forbade keeping the extra eggs and sperm after artificial insemination.
See question no. 174432
Because of that, it is forbidden to freeze and preserve ovarian tissue.
Our advice to you is to hasten to get married and to seek medical treatment that works to increase fertility; you should also pray a great deal for forgiveness and do a lot of righteous deeds.
In addition to this, you must also tell any suitor the truth about your situation because he has the right to have children and he may miss out on that. See the answer to question no. 125910
And Allah knows best.