Yes let the anger in, let yourself know that you are angry and that it is a feeling that will pass. Do not make any decisions based on this feeling.
Your thinking about your wife and its affecting your mood. You need to focus on you. This is why detaching is so important. This is why looking out for you and your son is so important.
If the picture are triggers I think you should take them down. It will help.
Me late 30's W mid 30's T 15, M 10 S4, S7 ILYBNILWY June 2015 In house S July 2015 W rings off Oct 2015 My ring off Feb 2015 Separate houses June 2016