Do I have to wait for all my inside scar tissue to go before I have a breast fat transfer?

There is no textbook answer here set in stone.  The longer you wait, the more likely that your body will have cleared any residual bacteria.  If you are still firm and lumpy, you may want to wait longer, and even consider if fat transfer is the way you want to proceed againBest of luck!
Dr. SubbioBoard-Certified Plastic SurgeonNewtown Square/Philadelphia, PA

I would suggest waiting a least a year to allow neovascularization of your breast.  You want to make sure you have well vascularized tissue before doing the fat transfer.

It is not possible to give a detailed answer given the information here, but you can certainly have additional fat transfer six months after your first.  If you still have lumps in your breasts, how they are managed really depends on how large they are and now many.  Larger lumps can be liposuctioned out or excised.  Smaller lumps frequently go away by themselves with time and sometimes the assistance of massage.  I my experience areas of fat necrosis are frequently misdiagnosed as being infected as they can be red and tender due to inflammation, not infection.   Having many lumps after fat transfer is not normal and I would recommend consultation with an experienced surgeon to minimize your risk of this complication.