The constant swishing sound in ear, with ringing & light-headedness may be due to:
1. Infection/inflammation in the ear.
2. Upper respiratory tract
infection spreading to the ear.
3. Intake of drugs which can cause damage to the hearing apparatus (Ototoxic drugs)
4. Systemic causes like abnormalities in blood pressure or blood sugar levels.
So...it will be better to consult an ENT specialist
& get a proper physical examination done.
Intake of self medication
or OTC drugs may be harmful in this regard.
Wishing you a Good Health. Let me know if I need to clarify further.
Thanks & take care.