Low sperm count and the viral infection do not seem to be related. Low sperm count is even before your husband had this viral infection.What is the count? What about complete semen analysis?
Has he undergone any investigations? The reports are needed.
Does he work in a very hot atmosphere like near a furnace? This decreases sperm count.
Please get him examined from a
urologist to find out whether he is having
varicose veins in the scrotum. That also brings down the sperms.
Moreover, you are also having irregular menses. Your work up is very important. Please find out first whether you release eggs regularly or not. For that your
hormonal estimations in the blood is required. Also study of the lining of uterus reveals so many things. Have you got it done? If the eggs are not released, IUI cannot help.
Frankly, in
infertility, unless all these investigations are done and there reports are available, correct guidance cannot be given.
Please get these investigations done and ask me direct questions when I can guide you properly.