does anyone have recommendations on products for my straight but dry hair?

My hair is very long but my ends aren't that healthy and it thinned out over time due to stress and all. I usually oil it once a week because I only wash it once a week (I've noticed it keeps my hair nicer) and I want to start using a product to make it nice and straight. It is naturally straight but because it's so dry, my hair keeps having random split ends that stick out (idk how to explain it, almost like frizz) it's not very silky. I want healthy hair without chopping it, any recs?? Also, when I go to get my haircut they blowdry it and its so nice and silky and bouncy, I've asked what products they use and she's never too clear about it so I can't tell. Whenever I do blowouts myself it turns out the same looks wise, but it def isn't silky and smooth like they do at the salon.

- If needed, I could attach photos of what my hair looks like versus how I want it to look like