My hairdresser messed up my hair its sort and uneven, i need help?

Ok my hair is bad, its uneven, short(at my shoulders or jsut above) its fryed rly puffy and wavy, now i jsut learned like 2 mins ago my younest sister has lice-ewww, so what can i do at home, i dont want to go to a hair dresser cuz if i have even like one lil thing and i if i so have eww lice how do i get rid of it