Missing that special friend

So.. I am married. I had a 'secret' friend/affair that has ended in the last while. I don't believe I was built for an affair. It was stressful for me but we had built an special friendship and support for eachother. That is gone and I miss it. Do I search for a portion of what we had with someone else? Like an online friend? Or try to get over this missing piece. Any applications welcome. Lol.