I am sorry to hear this.
If you spouse breaches the separation agreement the solution it not actually that difficult. So don't be afraid of his bullying tactics. And it is vital that you are always honest and never write a letter for him with numbers that are not fully accurate.
He can use the Separation Agreement to prove what support his is to pay. He can write off this amount as a reduction from his income. You have to declare the same amount and pay tax on it. If the numbers do not match the CRA will audit both of you. It does not hurt you to write the letter as it is going to set out the truth only.
He may have been asked for it by the CRA as that is not at all uncommon.
If he breaches the agreement you simply seek to enforce it through the court.
And the reason why I say simply and that is not difficult is because there is nothing to fight about. The court takes the agreement essentially turns it into an order. Then you register this order with the Family Responsibility Office and then the support will go through them. If he doesn't pay them exactly what the order says each month they will garnish his wages, seize bank accounts, can seize assets and will suspend his licence and passport.
Here is a link to some information that will help you:
Does that help as a starting point?
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