It is important to see your doctor or psychiatrist in the first instance. If you are not up to arranging an appointment yourself, ask someone to arrange an appointment for you. Your doctor is your first port of call when it comes to any illness, including depression. Your doctor can make an initial assessment of the severity of your condition and advise you accordingly. It is your doctor who can issue your employer with a sick note, prescribe you anti-depressant medication, and/or refer you to a psychiatrist or psychotherapist.
Most cases of depression can be treated without hospitalization, but in very severe cases, your doctor may advise you to go to hospital for specialist treatment.
If you are not happy with your doctor’s diagnosis and recommendations, then you are fully within your rights to obtain a second opinion from another doctor.