Halaalah

Q: After a man divorced his wife, if he wants to remarry this woman then is it necessary for the second husband to have sex with this woman for her to become halaal for her first husband?

Getting married after the iddat period

Q: My husband and I have been separated for a year now. In May this year, he sent me an sms stating "I am giving you 1 talaaq in writing so you cannot deny it". We have not had any intimate or sexual contact in the last year.

My question is: Is my nikah over and am I allowed to re-marry? I understand that my iddah started from the point where he gave me this one talaaq and lasts for 3 menstrual cycles. The 3 menstrual cycles are over now but I did not observe iddah in the correct manner as I did not know at that time that I was in iddah.