Why Did I Have Cyst Inside Of My Vagina?

hi i am 23 yrs old, i had an abortion last month on 6th i was supposed to get my periods this month but i didn't get it. i went to the doctor she found cyst inside my vagina and she gave me an injection for it and ,medicines though i got ma periods but m very depressed and scared! if m gonna be back to normal or no? please help.. F