Even after my baby's clip she still had a tendency to keep her tongue very far back so we had to do suck training with her for quite some time. You put a finger in their mouth, and then turn it over so that the nail side is down, while drawing your finger forward and out of the mouth to encourage them to stick their tongue out farther. :P
Even though it wasn't totally better after the clip, she gradually got used to having more freedom of her tongue, and now it seems to be fine. I hope you find a good doctor! Have you checked with dentists also? I have heard that some pediatric dentists will do it. The ENT that did our clip said that a lot of times she sees girlfriends dragging in their boyfriends to get it done because they aren't very good kissers; she also sees toddlers come in because they are having difficulties with speech. So there are more reasons to do this than just the nursing.
I will pray that you are able to find a good doctor and get an appointment quickly.