I need hair help

Hi! I have this problem with my hair. My hair is like wavy curly. The thing is, is that it is SOOOOOOOOOOOOOOO dry!!!! I use this oily thing to make it more oily. It does work, but there are some bad things to it. I really like the natural color of my hair (golden brown), but when I use the oily substance it makes my hair a lot darker. Also it makes my hair feel weird. I sometimes straighten my hair and I have to use so much of the oily thing to make my hair stay together. If I don’t use it my hair ends up really puffy and fizzy, which looks really bad. Does anyone know a product that makes your hair oily without changing the hair color or anything like that? I really need help!! Thanks