Whether sufficient or not, you enter the total income number for all three years, in the tax section. Yes, same even if filed with your ex. If the loss is an outlier, then your current income would be your gross salary for a pay period times the number of those pay periods in a full 12 month period. (bi-weekly times 26, for example). Tax section is about the past. Current income is not about the past.
Current income is documented with your pay stub, not your tax return, unless you are self employed. Looks like you are both employed and self employed, but you qualify anyway.