Cholesterol/saturated fat will clog your penis arteries which is the leading cause of ED. (In fact ED is one of the first symptoms of heart disease, the No.1 killer.)

Nutrition Facts has a page about testosterone, I'd suggest you start there: https://nutritionfacts.org/2017/05/16/foods-that-affect-test...

edit: link to a video about ED vs diet: https://youtu.be/OVXzT_RBxFk