Hi,
Problems you are describing can occur normally with anyone especially when they are going through a stressful period. There might be traumatic events in past which might be bothering you. But if they are too frequent and causing discomfort then it might be a symptom of an anxiety or depressive illness. You will need to consult a Psychiatrist to describe your worries in detail based on which future course of action can be decided. If its mild depression then counseling and psychotherapy can suffice. If it's moderate to severe then medication may be needed. You can try to make changes in lifestyle which will also help.
Next Steps
Detailed evaluation by a Psychiatrist
Health Tips
Try relaxation exercises and talking to friends and family.