I find it funny that I get so many questions similar to your question. Please note that your marriage vows are till death. So, unless one of you has died, then the marriage continues to exist even if you are no longer living together as husband and wife.
If you want to look at it in another way, your marriage contract does not have an expiry date, does it? So, no matter how long you and your husband have been living apart, your marriage still exists.
Kasi, the existence, subsistence and the validity of a marriage is a legal matter. It cannot be left to the discretion of the parties kung hanggang kailang may bisa ang kasal. Nakuha mo?
Kung ang bisa ng kasal ay nakasalalay doon sa mga ikinasal, eh, di, kung ayaw na nila sa kasal nila, puedeng basta maghiwalay na lang sila -- hindi ganoon, eh. Ang bisa ng kasal ay isang legal na bagay -- tanging ang mga husgado lamang ang puedeng makapag-deklara na wala nang bisa ang kasal. So kahit isang daang taon pa ang paghihiwalay ninyo at di ninyo pagkikitang muli, kung walang deklarasyon mula sa isang husgado na ang kasal ninyo ay walang bisa, kasal pa rin kayo.