You're looking at this as a mountain rather than as a gradual process. There's no reason to rush into things with another woman, though I understand that it must be difficult to not have your wife around.

Meet people as friends. Join groups (check out meetup.com for ones in your area), maybe try a singles club. Pursue things that you're interested in, meet people that are interested in them as well, and work from there. There's no reason to hurry.