My LONG blonde hair is getting damaged and unmanageable?

i have really long bleach blonde hair (about 5 inches past my boobs) and it used to be sooo healthy but ever since ive been swimming EVERYDAY and going to the beach, etc. its getting really.. mushy and dry, and split endy :( i just gave it a little trim but it still looks terrible. WHAT DO I DO? i dont want to cut my hair short, i want it to grow to my waist!! ill be dying my hair a little darker soon, so