Hi there. Headaches in your case could be attributed to liver disease only if you have Ammonia levels building up. That said , increased ammonia levels is known to cause generalised easy fatigability and slowness of activities , increased sleep rather than a headache. Do you have any difficulty reading /seeing near or far ? If so you might be having a problem with the eyes in the form of Refractory error or may even have a raised intra ocular pressure- what is known as a glaucoma. So i suggest you get yourself worked up on those lines. An eye check up and if that is normal - a serum or plasma ammonia levels. Hoping this helps. Take care.