What Causes Excessive Weight Loss Along With Severe Hair Loss?

Hello,I am a gal of 25yrs age...i lost 18kg weight in 4to 5 months...the problem of hair fall started after 3 months of gyming...not dat tym...its 7to 8 month having hair fall with thinning of hair...the hairline is receding with less hair in the frontal and little part of temporal scalp...m having dandruff too...m taking treatment for dandruff but please sujjest me mesoscAlp works or not as i m having my marriage in may