So sorry to read your post Gwapito. I was fortunate when in a similar situation some years ago that my girls were old enough to make choices, so she had to go and I kept the girls.
From what you say it seems that she wont be able to cope when mama goes in August so I think it's important that you stay where you are for the time being.
I totally agree with Grahams 3 rules and suggest you take legal advice immediately.
Don't do anything silly and think of the boys at all times. They need you.
My very best wishes
