Be flexible and open-minded
Your choices: finish your project first;
At the same time, talk to your family about your plan, get their support;
and talk to career mentor/consulter.
Give your boss and co-workers some hints or indications that your are not happy with your current job/project, but you enjoy working with them. You are family-orientted, and want to put your family at the first place. People will understand you.
If I were you, I would let people around me understand my situation first, and then take action accordingly.
