When dealing with curses you first want to use a banishing ritual to help clear the energy coming towards your direction or the direction of the person experiencing the curses. You can use any banishing ritual you want but I have two banishing rituals I use which are the lesser banishing of the pentagram and the sword banishing ritual. Both of these banishing rituals invoke angelic forces to clear negative energy coming towards your direction. The sword banishing ritual can be learn from Damond Brand magickal protection book but the lesser banishing ritual of the pentagram is free to learn and you can access it online thru google or better yet free on this forum.
Second base on your experience and practice I would suggest you call on your protector spirits to guard you from the curse but the 4 Archangels Michael, Raphael, Gabriel, and Uriel can easily destroy and get rid of curses and hexes so calling them thru prayer or ritual so be your second step.
Third a cleansing bath should be next. Any cleansing bath with herbs and minerals should be able to help you rid of any curse energy remaining.
Last step is setup protection spells. I recommend the protective planetary pentacles of Solomon. A little research on this forum or Google should help you with this. This is talisman magic and very powerful.
If the folks continue to attack follow all the steps again but setup a mirror spell To throw back anything they send your way or your friends way. Hope this helps.