Are you filing joint? Or are you in a community property state? I ask because you said you are unable to get your future ex- husband's income.
Take the advice of Super Champ @Opus 17. He says leave your spouse's social security number blank. I assumed you will be filing separate. You will not be able to file. That's good, because you might want to attach a statement explaining why you cannot get the Social Security number.
I dont have my wifes social security number and she wont give it to me
If you live in a community property state and need your husband's income for adjustments, @Opus 17 suggests getting a lawyer. "Don't struggle with an uncooperative spouse, that's what attorneys are for," he said.
When filing separately, you only need your spouse‘s income to determine your qualifications for the premium tax credit. There may be a workaround to leave it off, or maybe just guess a high enough number that you won’t qualify for the PTC if you already know you don’t qualify. But you won’t be able to e-file without a Social Security number. You will need to file by mail and attach a written statement that gives your spouse‘s name and address, any other identifying information that you have, and a brief explanation of why you don’t have the SSN.