Absolutely you can successfully raise an older child having been a scapegoat yourself. You now have the gift of wisdom you can now share share with your child if you do your own emotional self growth work.
From now on observe your own behaviour to be sure you are rewriting the script you have come from. Attending ACOA (ADULT child of dysfunctional or alcoholic families) meetings could also be very healing for you. I suggest you share your learning with him. Also check out the ACOA laundry lists (before and after recovery) on Google and get the ACOA excellent big book.
Share key pieces with your child and discuss openly if he experienced any of the behaviours described growing up with you. This allows him to learn a new way of living with you and to express any angry feelings he might feel.
Please have compassion for yourself throughout after all how could you have known how to be different as a parent until you had awareness that what u had experienced as a child was dysfunctional and damaging.
Good luck with this beautiful journey of discovery with yourself and your child that's ahead of you.
For more information about the subjects covered in this blog, contact Margaret Parkes - phone: 086 832 0422 email: firstname.lastname@example.org