Dear IF you are married then you have married upon taking the responsiblity of you wife and to be children.
I think there is something in your thoughts and way of thinking, I suggest you must see a psychiatrist to have good advice than asking people around you.
Get Some expert advice and medicine and you will be allright enjoyoing your life with your wife and child.
If you are muslim then Read Quran, If you Christ go through the Bible and get divine help to get rid of such thoughts-Children are God's Gift only fortunate couples are blessed with.