I'm going to chime in with the others here....but I'm going to add something to think about. There have been times in my current M and in my past where any sign of true-genuine feelings from my H would have done wonders. Are you angry with me? Fine, show it....do you love me? Fine, show it. I guess what I'm saying (without making this too long) is that it may possibly be confusing her that she knows you are angry with her...but you don't show it, she knows what she's done/is doing is VERY wrong....but she's not really seeing the hurt/anger that should go with what she's doing to you.
Now, I know there's loving consistency....and I do think you've done wonders at that, and it's definitely necessary....BUT (and this is just my opinion here), if I were here....seeing some of your hurt/anger would have somehow (for me) shown me that what I had done really did hurt you. That you cared for me enough to be angry about it....too much loving consistency could almost be perceived as....being a doormat (sorry if that sounded harsh).
I really do think you've done AWESOME!, but it might just be time to show some of the emotions/feelings that should correspond with what's going on too.
I'm really not the best to advise on this...never been cheated on (that I know of) and never cheated...so I'm sure there's others better suited to advise you here.