Well, I hope you don't take this as a discussion on the wisdom of starting a new relationship too soon.... though it might touch on that a little, I do think it addresses your question.
My X had walked out, and then wanted to come back a few days later. We were going to counseling, but he didn't seem to be trying very hard, and I was very discouraged.
I looked up an old college boyfriend with whom I hadn't been in contact since shortly before I was married. He was one of the only old boyfriends that, though I had broken up with him, there were regrets. In fact, I still feel that were I to move back to my home state, which is where he is, that we might end up together eventually.
We started e-mailing a LOT - sometimes a couple of times a day - and I started feeling more and more like I was ready to call it quits with my (then) WH. I wasn't seeing progress, and my friend from college was making me feel a LOT better about myself. I started thinking that he had boosted my self-esteem, and that was giving me the strength to start contemplating divorce.
I started trying to look honestly at things, however, and realized it had nothing to do with giving me strength. I was starting to go into my own fog... sharing emotionally with friend from college.
At that point, I made a promise to myself that I kept - I would not consider ending things with my WH unless he started cheating again. That was basically the promise I'd made him when he wanted to come home - that I wouldn't let him come home, but we could work on things as long as he wasn't living with/seeing OW anymore.
I made sure I told my friend that's what I was doing too - he had been telling me a lot that he felt I was right to (biblically) and should divorce. While he was right to a certain extent, I realized that if I quit at that point, I would always question if I'd done the right thing, or if I'd done it because I started my own EA.
As it turned out, X and never QUIT living with OW, and was lying all along. I started down divorce path at that point. But at that point, I realized it was a clear decision on my own based on the fact that I no longer had any way to build trust in him again, and that all the evidence I had pointed towards him being a serial cheater.
Bottom line here? I think getting strength from someone else like that... well, that it isn't real strength. That you aren't really dealing with the issues. I know with me, when I went through that first phase of considering divorce, I felt like I was "over" him, and was glad my friend had helped get my self-confidence back. Later, while I was still very grateful for that friendship (which I still continue...and is still just platonic, long-distance, mostly e-mail,) I realized that I was extremely wrong about being "over" it all, and had a whole lot of pain to go through.
Still, I do think you need the strength of others to help you make that decision if it becomes necessary, and to get through the divorce process. But that strength should come from family and close friends (a lot of mine were friends from church.) Mixing romantic feelings in it at the same time.... well, I personally think that while it may help you get through it, that it just postpones the pain of really dealing with it all.
