I don't think I'm exactly "selfish." But I find when I'm making myself the center of things... for example, thinking of the affair as what my husband "did to me" or, "why wasn't I good enough," or "what was wrong with me".... kind of like being self-absorbed and the center of my universe... then I tend to fall into a sort of self-pity, blame, and relatively depressed state.
while if I separate myself out of it... really look at where my husband was developmentally (the whole MLC thing), his weaknesses, his experiences, influences, etc... then I have an easier time forgiving, realizing that everything wrong isn't entirely my fault and this isn't all about me being unlovable or that there's something wrong with me that caused my husband to do this...
I can see what's good in my husband and realize his weaknesses too. I can look at him more objectively and love and accept him in spite of the negative. Taking out my ego and self-centeredness makes this easier.
P.s. by the way, I have become more self-centered in a different way. I now do more "pampering type" things for me. Like buy new clothes, get my eye brows waxed, etc... similar to how I had done before kids. But I think this is healthy and something I needed to do.
There is no arriving, ever. It is all a continual becoming.