No, I do not think this means that you have to divorce your husband so that he can remarry his first wife. His first wife may never want to re-marry him. They got divorced for a reason. I will do some research and get back with you on the subject. But in the meantime ask your Pastor. Your Pastor is the watchman over your soul.
You have to remember, God hates divorce, but God forgives divorce. Divorce is not the unpardonable (unforgiveable) sin. God would never command His children to forgive if He was not going to forgive. God will forgive divorce. I do not condone divorce, but divorce is not, I repeat not the unpardonable sin in God's eyesight.
I stand on the Word of God. But we must know the Word of God. Do your homework. Seek God’s face and get in God’s Word for yourself. Talk to your Pastor and ask him what does this Scripture mean.
Encourager ###, M.A., LM, CS.