Interesting post. judging from your responses, many others thought so too.
it's a thought among many men that it's best to date a WIDOW. Common thought is a women who has been happily married for a number of years (whose union is interrupted by her partner's demise) won't have the baggage that a woman who has been through the messiness of a divorce.
By no means do I feel you did the wrong thing in any of the cases you brought up in your post.
Hang in. If you really want a relationship, you'll have one.