Being inside a bomb shelter in your dream means you need to protect yourself from unexpected ridicule, sadness or anger. Someone's anger or frustration may be affecting you negatively which could end up hurting you emotionally or physically. Your dream is alerting you by placing yourself inside a bomb shelter to shield you from this or some other type of pain, rage, mockery or misery caused by someone.
If you dream of a bottomless pit, you are feeling hopelessness and despair in your waking life. The bottomless pit may be indirectly referring to your conclusion and acceptance that an issue has overcome you and is never-ending.