Getting angry with your children wasn't wise, because they love you and have your best interests at heart. And someday you'll probably need their help, so why alienate them? The Bible rightly warns, "stirring up anger produces strife" (Proverbs 30:33).
But the real issue is your decision to move in with this male friend, and I certainly share your children's concern. I know many today think nothing of living together or ignoring traditional moral values. But God takes such values seriously, and He does so for a very good reason: He loves us and knows what can happen when we turn our backs on His moral standards.
After all, marriage is one of God's greatest gifts to the human race, and we treat it lightly at our peril -- no matter how young or old we are. Have you ever stopped to consider what impact your example may have on others, especially your grandchildren? It would be tragic if they end up taking marriage lightly and blaming you for their attitude. The Bible says, "Marriage should be honored by all" (Hebrews 13:4).
But your letter concerns me for another reason: It suggests your only concern is for your immediate happiness, without any concern for God and His will. Someday soon, however, you will enter eternity and stand before Him, and you aren't prepared for that day. But you can be, by repenting of your sins and giving your life to Jesus Christ -- beginning today.