I have mousy blonde hair naturally and have been getting highlights since I was 18. However recently it has become very knotty, tangled, dry and unhealthy. During pregnancy I didn't get it dyed and the natural hair that has come through is so shiny and healthy in comparison so I decided to grow it out. However I really really hate the colour and miss my blonde hair so am thinking of getting it dyed again. How can I keep it healthy?