Banging My Head Against the Wall

I remember so distinctly thinking it would be fun to own a horse. And it has been. But it has also been one of the most frustrating experiences of my entire life. Wanda is in pain, again. She began getting more and more girthy before the snow three weeks ago and I was going to ask my trainer at my next lesson if she thought we needed to get the saddler out. Well, the answer would have been yes. She's so sore now that just laying a hand flat on her back practically sends her through the roof. I quit halfway through my lesson today because I just didn't feel that it was fair to her to keep working. My trainer has also suggested that I call the orthopedic vet to see if anything can be done about her interference behind. I have an appt. on Monday and I'll post what she says. Now I'm feeling bad because it never even occurred to me to worry about the interference beyond getting protective boots on her. I didn't know doing something about it was even an option. But frankly it's the back that has me banging my head against the wall. Even when we got the new saddle this fall and it fit better and she was much more willing to swing through her back it was always tender. I'm not certain she has ever NOT been in pain and that is really frustrating for me. I'm in tears over it and I just don't know what to do beyond what I'm doing. I have a call in to the saddler so we can hopefully adjust the saddle fit again. Poor mare.