Your vow is not in Scripture. There is no place in the Bible that says "Until death do us part".
That is your personal covenant. Christ says marrying a divorced person is adultery.
You are bound by your vow to God regardless.
I think that you are splitting hairs here with marajade. You are correct that the wording of the typical marriage vow 'til death do us part' is not mentioned in scripture. However, there are several places where divorce is mentioned in scripture and the conditions under which it could be applied. It is certainly made clear that it is only for the case of adultery and even there, it is not automatic as the couple still should work things out under a spirit of forgiveness. One is left with the distinct impression that while there is a tiny 'out', it would be incredibly rare if scriptural instructions were followed. So, if divorce is something that should never happen, that automatically implies that when people get married, they are doing so for life. If the understanding is that they are getting married for life, then a vow that states 'til death do us part' is simply vowing to do what the Bible is commanding us to do isn't it?