You didn't mention whether you are experiencing any pain, inflamation or infection. Have you been to a doctor about this problem, specifically, an ear, nose & throat doctor?
If you are experiencing something akin to your voice just 'going away' and then 'coming back', then you might want to get checked out for a voice disorder called spasmodic dysphonia. It could also be allergies or stress causing your voice to be weak.
I wouldn't mess around with any 'home remedies' -- your voice is well worth the expense of going to a doctor.
I hope you feel much better soon, Áine