I have several things to point out.
First, just because a dream is "awful" that does not mean it's not beneficial. Perhaps your Labradorite is bringing some things up from your depths that it thinks you are ready to see. If I don't know what a dream means I will often use the Tarot to help me understand it. Oftentimes they are not what they appear on the surface.
Second, if your dreams are not beneficial in some way, then I would make sure your crystal is cleansed. These things pick up bad energy like magnets which can spread to you in your dreams so it's always wise to cleanse them regularly.
Third, make sure you are setting your intent before sleeping. Ask your guides for protection during your dream state, ask that you will only interact with positive service-to-others entities, and ask that all energy will be in alignment with the highest good.
Lastly, Labradorite is a protective stone so you should not need another crystal for protection, but if nothing else works try incorporating Obsidian, Nuummite, Smoky Quartz, Magnetite, Black Tourmaline, or whatever protective crystal you use into your sleep routine.