If I have been married less than 2 years and might want a separation from my husband, will he still get a green card?

He can still get the green card even if you are no longer married if he can prove that the marriage was legitimate and bona fide and not just for immigration benefits. As far as support, unless you are ordered to pay spousal support as part of your divorce case, there is no support that is required as part of the immigration process.

Potentially, if the bona fide nature of the marriage can be established to the satisfaction of USCIS. However, assuming you have signed the I-864 Affidavit of Support as a "sponsor" on his behalf at the time that you filed for him to get his conditional I-551 "green card" you will still have a legal obligation to the U.S. Government for the ten-year period of the contract if he should become a "public charge" and be unable to support himself. You should consult with an experience immigration lawyer to guide you under the circumstances that you describe.