Hmmm, I don't know, I've kind of felt like this, although I had stuff to say, I just couldn't decide what to say and was too frightened about what other people would think to say anything. Maybe you have hidden feelings or thoughts that you arn't revealing about yourself that needs to get out before you can communicate properly. Maybe you need to change your outlook from yourself to other people. What are your hobbies, likes, dislikes, things you used to enjoy, talk with people about them. Ask people questions, alot of time people like talking about themselves. Getting on an anti-depressant from your doctor could be a good direction to go. Although sometimes it tough to start because you have to try different ones to see which one will work for you. But that might help you get over your feelings of emptyness and get you out of the slump your in. Also maybe you need to search for your spirituality and your identity. Find a higher power, or a higher reason for living. Try focusing on the problems, needs, and desires of someone else and helping them. Mabye you just need to be a friend to someone. We are all connected in some way, through the things we find interesting, go out and get connected with people that have the same interests as you.
Also, if you had nothing to say, you wouldn't be able to make a post like this. You obviously have something to talk about.