Since you have not applied and appear not to have a spouse willing to sponsor you, your best chance at a green card is with employer sponsorship. File for a divorce; alimony is not generally an issue for a short term marriage. Remaining married does nothing for you at this time but make you possibly liable for his debts depending on the laws that apply in your home state and the manner in which the debts are incurred.
The fact you are more interested in a green card than your marriage is very telling.

