Your expectations are definately too high. Hand launching a glider at ground level is exactly the same thing as throwing a paper airplane. There are no thermals that low to the ground. Repair your plane, and ask at your local hobby shop if there is a club in the area where you can ask questions and get help. Even if you don't join, they may have a few glider fliers that can tell you where some good slopes are, or maybe they have a winch, or a Hi-Start (giant rubber band kind of thing) that they can get you up high with.