Masturbating Just Isn't Working Out

Okay..... So I did that a few times a LONG time ago and it felt good. I tried a few times about a year ago, and....... Nothing.

A few months ago, my (now) exboyfriend and I began sexting. We would send each other pictures of our privates and videos of us masterbating.

It used to feel SO good whenever I was masterbating for my ex. Now, not so much. What do I do?