Family ... may be a blessing or a curse depending on karma. I can relate my experience with a very negative family so I'll try to add some insights here.
You don't specify what kind of curse/problem you have so not easy to understand.
In my experience, generational negativity is most often feed by the family members. In my case, it is like a sort of "family mass mind" took over other family member's minds, and this is constantly reinforced by their will. By continuously putting energy in this, with their thoughts. And we know thought have energy and energy ammassed for a while can manifest. What I perceive is, they constantly feed that family "monster" driving family members to negative lived. I could call this an egregore or maybe it's simply a curse - as you say - that keeps feeding its energies.
I do think Munka works but for me it's only a part of the process. First and foremost it might be advisable to detach from family members, both physically and spiritually, to avoid being continuously drawn in their negativity. Then you can work on cleaning out the problem, from a stronger position. I don't know if it's your case, detaching, you only know situation in details. But staying in the middle of negativity is not the best position to work for healing it.