brittle&frizzy hair/pitted nails

Hi. Over the last few years my hair has gone from lovely, straight and shiney to dull and tatty. I get split ends easily (just had my first of a few trims to remove them). I have what seems to be new growth in certain spots that are really sort and curly/frizzy and they pull out without any pain. The longer hair is breaking off easily and feels wirey and is sometimes straight with a frizzy end. Some bits are coarse and pull out with no pain. I have tons of chunks that just look like they've been torn part way up the strand (or like a whole chunk fell out and is now growing back). I also have little indentations on my finger nails but no white spots like you'd expect if I was zinc deficient. Can anyone explain to me why my hair/nails are doing this? Many hairdressers just can't answer this for me. I have had my thyroid checked and it is fine. Thanks for your help!

You probably don't want to hear this, but a one off short cut might be the solution here. That way the hair would probably grow back more healthily.

Hi everyone, thanks for all the replies. I haven't had any diet changes over the last couple of years. I'm guessing the only reason could really be a mineral or vitamin deficiency. I'm guessing zinc would be a good one to try first. I'm having another trim next week and this will rewmove the bits that are frizzy at the ends of the lengths, but they are actually growing like that now too, so cutting it wouldn't help. Lets hope the minerals will help!!