As you know, long term daily, or near daily, use of acetaminophen is problematic. NSAIDs can also cause problems, not only erosion, but also liver damage. What preventative drugs have you used? Keep in mind that (like NSAIDS) the preventatives sometimes need to be rotated: i.e. if a drug stops working, change to another, and come back to it later. Sometimes people get discouraged if they have gone through multiple preventatives (i.e. beta blockers, calcium channel blockers, etc.) and they've all stopped working, and they don't realize that they can come back and circle through that drug list again with good results. Talk with your neurologist about CAM or herbal supplements that you can take, since some of those are helpful, but your health history may preclude some of them, too.
Do you have any ideas why your migraines have worsened recently? There's always some reason, it just takes time to find it sometimes (e.g. dietary or exercise changes, stresses at home or work, hormonal changes associated with pregnancy or perimenopause, etc.) You will need to continue addressing the depression, as well. Being discouraged about migraine pain is one thing, frank depression is another, and that depression can only make the misery associated with migraine pain worse.