Im 14 have had thrush for about 5 months without knowing for 3 months is it harmful tht ive had it for so long?

Im Scarlet and i have had thrush for 5 months maybe 6 months but for the first 3 months i didn't realise until i saw an advert describing the symptoms, is it harmful that i have had it so long and not treated it. PLEASE HELP I REALLY NEED IT THIS HAS BEEN HAUTING ME FOR THE PAST MONTH OR 2 !!!!!!!