A sponsor's role is to guide the sponsee through the 12 Step process - this is where their expertise lies.
A sponsor is not a therapist or a counsellor so cannot fulfill those roles. If a sponsee needs extra support from counselling/therapy then a sponsor can easily work alongside that.
I am sure you will be able to find someone who supports the outside treatment you are getting. There are plenty within AA who have counselling and therapy. And there are plenty of counsellors and therapists who support the 12 Step program.
Good luck. Keep in touch.