Practice, practice, practice. The more you practice the better you get and try out small things first. Don't try and contact people like a thousand miles away at first. If your in Maine and they're in Oklahoma it just won't work. Try out small things first. Then move to big thins and it might also help if you look up telepathy on google.
Well, it sounds like you are on the right track because of your headaches. That is said to be totally natural. I think you will reach your goal. Sounds like you are persistent. You know, from my experience, visualization is very important in any workings. Well, if you are trying to accomplish this, it is working in some way. That is the way these things are, they work in some sort of way. I would have an item of the individual; such as, a picture or some thing that person had and held onto (something that carries their vibes). Then I would imagine building up a thought that says, hi or hello. Then imagine that thought, that image, going to the person in your meditation, while holding something of theirs (be persistent with the same thought or image). In the mean time, I would practice this with your friends, in person. When you practice with your friends, on this telepathy practice, you do the same thing, as I mentioned. Sit across from each other, and visualize a simple object or number, then visualize that thought going into/onto the person's head. Your eyes can be open or closed. The friend you are practicing with, will need to ground themselves, and just sit there, saying what comes to mind. You know, I cannot speak for this as truth because I haven't tried it, but I will say it sounds like fun, and I am trying to help you.