In the beginning this is quite normal. Often times when one first begins to meditate one becomes a bit depressed by what they see going on within themselves. It takes courage to be able to confront the garbage one has been continually stuffing within the subconscious. It is not easy to see that they have been masochistic and unloving towards themselves. To sit in meditation is to begin to love oneself. To respect oneself. We have been conditioned by the societies in which we live to sacrifice ourselves instead - to be good cogs in the wheel of society, which requires one to act in a machine-like fashion. To come out of that mold may feel a bit strange in the beginning. It is only because one has grown accustomed to the habitualized repressive behavior - a self-imposed suppression.
You mention you have a cast on your leg. This must be prohibiting you from being as active as you would like to be. Meditation brings up to the surface moods and feelings that may have been present for some time. Usually, in our normal day to day existence, this isn’t noticed because we often times are continually engaged in activities that keeps us distracted, from being aware that such feelings are within us.
Try to include a way of being creative in your life. Art, woodworking, playing music, dance or some form of exercising the body (taking your cast into consideration), etc. Actually, meditation should really be our natural state of being. But the society has programmed us to be quite unnatural. Even our breathing is shallow and unnatural.
In the beginning it will take an effort before we unlearn the conditionings that have been imposed upon us. Meditation means unlearning that which has been taught to us unconsciously and imposed upon us consciously by others. Be sure to keep your meditation a non-serious affair. Experiemnt with it and keep it playful.