Another way to expand your receptivity during your meditation is to try to consciously feel inner joy. If you cannot feel inner joy immediately, then try to imagine for a few seconds or a few minutes that you have it. This will not be false.
Your imagination will intensify your aspiration and help you to bring forward true inner joy in the course of time. The very nature of inner joy is expansion. When you expand, your receptivity will automatically increase, like a vessel that keeps getting larger.