Leave in oil that won’t weigh down my extremely fine silk spider web hair?

My problem is tangles. It’s not dry or anything. I have reeeeally fine hair. Like, it’s silk. Can’t hold on to any hairstyle. Straight as a ruler. It gets SO TANGLY!!! I brush it out, an ant farts & my hair is tangly again. By the end of the day if I don’t carry around a brush it’s matted. My hair also seems to be really absorbent. High porosity is the term I think?

Is there any product to help this? Oil spray? I really have no reference I’ve never really put any product in my hair before. I’m a wash and walk out the door girl. Every oil I’ve tried makes it soooo stringy.