uneven breasts..

so the title really says it all..i have uneven breasts and i really dont like it..when i wear clothes, i dont mind as much because it's hard to tell, and if i'm wearing something that shows a little cleavage i'll put an insert into the cup with the smaller breast to even them out. but in the case of being "in the bedroom" with my SO, i get very insecure..i always try to cover them up with blankets or somehow position myself in a way that he doesnt notice the size difference..and the difference between them is about one whole cup size..
i just wanna know if there's a way to fix this so that theyre actually even but without having to get surgery..anyone know any ideas..? or is this something only my doctor can help me with..?