Hello. There might be multiple reasons of hair fall including diet and surroundings as you have mentioned. If you feel that hair fall is not stopping even after you have taken care of the diet, taking multivitamins as well as controlling stress, then there might be other conditions which might be causing hair fall in you. One such condition is called frontal fibrosing alopecia in which there is loss of hair in the sides of the scalp. This is one of the conditions. It could be that. Futher evaluation is required including dermoscopy/biopsy.
Next Steps
Consult a Dermatologist in person. You can start off a serum which would help in decreasing the problem. Consult me online if you want to.
Health Tips
Consult a Dermatologist whenever you are free. Multiple reasons of hair fall might have to be evaluated.