Google search homemade deep conditioners they are really easy to make and are made with cheap items like eggs and olive oil. I know it sounds gross but they work. Especially the ones with eggs and oil. when you use them make sure to leave it in for like half an hour and wash it out really good with shampoo. and if you want you can use a regular conditioner afterwards but it isn't needed.
Put Olive Oil all over your hair for a couple hours, once a week. Get trims every 3-6 months to keep the split ends off and to prevent them from splitting even higher. Leave conditioner on in the shower until the very end of your shower. And lastly, use leave-in conditioner when your hair is damp/towel dried after a shower. Also, It's recommended you use cold water on your hair to rinse, it's healthier than hot water and gives a slight shine, and less frizz.