I only say this because it sounds like the larger breast
is lower than the other.
It is great that
you don't want implants
, they were a disaster for me, had to have them removed after 10 years. Many, many procedures to resolve problems with implants.
I don't know how old you are, but as one ages, there is usually a weight gain. So as you get older you breasts will probably enlarge some.
Fat transfers have not worked successfully, it isn't that Doctor's don't do them and get paid for them.