Conditions for the validity of Nikaah

Q: I am born a Muslim but I got distracted at some point in my life and commited adultery with my ex boyfriend. However I got married last year with a virgin man. I did not repent before getting married because I did not realize that it had to be done. I have been realising my mistakes lately and I cannot tell you how ashamed I am of my past. I repented to Allah several times after marriage. 

Now I got to know that in the Quran it is mentioned that a fornicator cannot marry a pure man. I have also read that the scholars say that if a person repents, only then can they marry a pure man. As I have mentioned that I have repented from my heart and I still am repenting but it is after marriage.

Will my marriage still be valid? Or do I need to renew the marriage contract? My husband doesn’t know about my past. Please let me know what should I do now?

Q: Is it permissible in Islam to file the nikaah while the bride is in her menses (haidh)? Is nikaah jaiz for the girl in the days of her menses (haidh)?

Q: Can someone marry a second wife without taking permission from his first wife according to Islam?

Q: If a lady marries a man on a condition that he will not take a second wife and he agrees, will the nikaah be valid? 

Q: Regarding nikah witnesses on Ask Imam website it states:

The wakeel represents the bride in the presence of the two witnesses who must be trustworthy and pious male Muslims. They should not be from among the girls ascendants e.g. father, etc. nor from her descendants, e.g. son, etc. https://islamqa.org/hanafi/askimam/28924

Could you please explain the above regarding witnesses in the nikaah. Will the nikaah be valid if the witnesses of the nikaah are among the girls ascendants e.g. father, etc. or from her descendants, e.g. son, etc?

Q: I was told that a divorce in court is like a talaaq. There is no need for a separate talaaq. However if you make nikaah, is that valid or does one have to separately get married in court?

Q: My sister's name is Aay Bee but during the nikaah ceremony the Mufti said "Aay Khan" instead of "Aay Bee". I just want to ask if this nikaah is valid or do we need to do the nikaah again?

Q: I have done a civil marriage with a non Muslim girl who will convert to Islam, but has not yet converted due to some financial problem. I have tried to get the nikaah registered but they are asking +/- 10,000 for registering and certificate. Now I have one child. Kindly assist on how to get the nikaah properly and how can I correct my mistakes.

Q: I want to marry a second wife, do I need permission from my first wife?

Q: In a nikah ceremony for a new Muslim couple, one male adult wakeel on behalf of bride and another male adult witness were present. Is the nikah for both valid. Later this nikah was register in a madressa with a mufti.