The symptoms as mentioned in your post suggest that you might be having dysosmia
It can be attributed to:
1. Some medications like metronidazole
2. Exposure to certain chemical
3. Upper respiratory tract
infection in the form of common cold
or sinus infection
4. Poor oral hygiene
, anxiety, etc.
A proper examination of the nose & throat will be helpful in clinching the diagnosis.
So, it will be better to consult an ENT specialist
& get a proper physical examination done to rule out any organic lesion or any other cause in nose or throat.
So that appropriate management steps could be taken.
There is nothing to worry...you will be fine.
Wishing you a Good Health. Let me know if I need to clarify further.
Thanks & take care.