Infertility is the inability of a person, animal or plant to reproduce by natural means. It is usually not the natural state of a healthy adult, except notably among certain eusocial species (mostly haplodiploid insects). In humans, infertility is the inability to become pregnant after one year of intercourse without contraception involving a male and female partner.
Sorry to hear about your situation.
I just wanted to add that even in this day and age when we think we control everything with technology, life and death are still in the hands of Allah. I have known several men and women who thought they were infertile (or even had surgery to prevent children) who later had children. Similarly, some people who are fertile never have children.
So unless there is an obvious genetic or anatomical reason why it is wholly impossible for you to father children, sometimes the possibility exists.
Of course you know your situation best, and perhaps it is not relevant to your specific situation. I just thought I would put it out there in general - there are no guarantees - although sometimes we can get a good idea of the probability of something happening, and it makes sense for someone who has a strong interest in having children to maximize the probability of it happening.
You should be very honest, frank and clear with her about such matter if you are medically proven unable to have children. Honesty is more important than a deal of marriage with out informing the girl about an issue which is usually crucial for every girl who accepts marriage with a hope to be a mother in the future. Keeping her in dark is not acceptable at all. If you tell her the truth and she accepts it, then it is good and she can not complain in the future that you cheated her.
Thank you for your question. There is a difference of opinion on 3rd party sperm donation and so you must refer to your Marja to ascertain his view on its permissibility.
May you always be successful
No. Fertility is created by Allah to whom He wants and it is never a matter of superiority. Superiority is based on Taqwa (Piousness). Wife of Prophet Ebrahim and wife of Prophet Zakaria were not fertile during long period of their life. In Quran we read :ويجعل من يشاء عقيما (Allah makes whom He wants not fertile.) (Sura 42, Verse 50).
When it is from Allah, then there is no question of inferiority.
Just being unable to father a child is not enough reason for you to seek divorce from him, unless you explain the full reasons and refer to the Marje’ Of Taqleed or any of his representatives to assess your case.