My Fingernails All My Life Have Been Thick, Long And

My fingernails all my life have been thick, long and tough to cut. In the last couple of months I noticed my nails are thinner and breaking pretty easy. The thumbs have a horizontal dip in the bottom part, just below half of the nail. Also, maybe very thin lines going vetrtical.Could I be lacking something? I am supposed to have M.S. and have been on copaxon shots for 2 1/2 years. I take Nifedapine ( a blood pressure med.) That I take for hypoglycemic, the med keeps my sugar from dropping to the 50,60 when I ate low sugar and low carbs. Thanks!