Step II: Mourn / Grieve
You need to allow yourself plenty of time and space to grieve and mourn your losses.
This includes grieving over losses of your ex-mate's family (parents, siblings, etc.) and friends, co-workers, shared neighbors, etc. It also means mourning old family rituals you'd maintained and even developed together in marriage, crying when you take out a box of engraved ornaments during Christmas, for example. Mourning is natural, so feel and let it out. Don't hold the hurt inside.
If you feel the pain is too much to bear or find you are too depressed for too long, seek help. Ask close friends and relatives or your family doctor for referrals or check the Yellow Pages. A good counselor or clergy member may be able to help you sort out your negative feelings and overcome them.
Step III: Adjust
Next it's time to move on and make adjustments for your new style of living. Don't rush into 'change' but rather take time to investigate your new environment. Especially in the areas of relationships, you don't want to rush out and start dating and getting deeply involved right away.
Instead, let dust settle. And make sure to take a time out to see what happened with your failed relationship. It takes two to make a relationship, even if one party did major damage. And you don't want to repeat your mistakes by parenting up wrong again. So take time to see what went wrong.
Step: IV Rebuild
After you've had time to take stock in your environment to see what were the negative and positive points about your failed relationship, begin anew. You don't need to have a mate to survive and enjoy life. And maybe you'll want to not date for awhile.
Start a diary or journal about your new life and grow, allowing yourself plenty or room for new friendships first, then slowly try relationship building on deeper levels to see what you think.
Just remember, slow and steady does it. It's a process!