sorry to hear that the boy is sick, shows a great deal that your there for and taking care of him. the vm's from w seem to be getting pretty frequent. not sure if it is just s sick, i'm thinking it might be guilt while with the om. keep it up, he isn't going to take to kindly to the fact that she is friends with her h, and then he will show is bad side and that will leave you to shine.
as for your plan, i think it is good, except for the going dark at this point. maybe it is needed. i fully think that you need a trip, something fun. grab a couple of friends and go have a great party weekend.
also great with holding back any talk and keeping your cool when she does call, that will make it that much tougher for her to rationalize her actions. keep that going.