Hi OTMT, I'm new here but I've come out to make a comment as your situation is very similar to mine in some respect.
I know that your major 'issue' right now has shifted to porn but let me highlight something.

How often have you told your W that she is unattractive and the marriage was not based on love? (therefore telling her that she is/was not 'wanted/necessary')
Do you know that when someone is emotionally abused, many will become depressed and start thinking about taking their life?
And to stay optimistic in such a situation, you need a good support network around, preferably close family members or friends.

I think most of the issues you have may be coming from your lack of confidence... subconsciously you have been eating away hers to feed yours.
Everything else is a ripple effect of that.


The issues:
- different cultures: it needs to be understood that moving to a different country and learning another language are huge, life long tasks.
Some people pick it up fairly quickly, others never do, just like some love Maths but not everyone. It's much more difficult to learn when you are an adult.
When you married her, you knew that there is no guarantee she will learn English quickly or adapt well to your country, if ever at all. You took a chance together.
It also takes lots of time to study which has to be enjoyable… when does she ever have time when you have 5 kids??

- over protective of kids: do you know that mothers tend to be all over her children when she is not getting along with her partner or the partner is absent? Her full attention is turned to kids.
Also, she's continents away from her family who can otherwise give her love and support.

I mean with nearly all of the issues, it all grills down to your imagination and creativity… do you know how lonely it can be moving to another country, wondering 'how many times will I see my parents in my lifetime'?… how difficult it is to learn a language when you have issues at home (I wouldn't be surprised if she now dislikes being in your country… it's full of these difficult memories from the start, therefore learning your language is no fun either)… how impossible it might be to not be all over her kids when they are all she's got.

Do you ever try to imagine, instead of asking 'why can't she'?