I've always said it, that no knowlegde is wasted. And everyone has something he knows that can get him to where he's going. Every dog has its day. Just know what is your area of strength and competency, it may be a talent, skill, knowledge, or experience in something. You just know you are good at this thing.
Once you've discovered what it is, i can tell you what to do with it and how it can serve you. You can create your own opportunities from that thing, even start a business along that line. Believe in yourself.