You may be experiencing strong emotional repression during the day, or it could be that there is an undetected physical ailment occurring. Generally speaking, the occurrence of organic diseases will always have specific symptoms.
Dreaming that you were hit while riding a bike may indicate hidden dangers in your work, and you never know when you might get into trouble. For example, when you work hard, you offend a group of troublemaking colleagues who always try to harm you by sabotaging your work, making it difficult for you to continue.
Dreaming that a bus crashed into a small car may suggest that you have lost control of certain things. It could represent conflicts with someone, or internal conflicts. It may indicate obstacles in your development in a certain aspect, temporarily preventing progress.