Hi Sesara,
If it does turn out to be a thyroid problem, then as you said, there will be something that can be done about that, and then you'll feel better. But if that isn't the case you're still going to be okay. You'll just need to look at different solutions. And you seem to be on the right track with therapy, medication, and it sounds like you have a lot of supportive people around you.
All I can suggest is trying to stay active (which can be hard when you feel low) and talking. My mum used to tell me that putting out energy leads to more energy. Meaning that it's hard to get started, but once you do things move more easily. I've found that I have to push myself to get things started, but if I manage to keep going it gets easier, and then things start to get done. And on days where you really can't make yourself do anything, then talking. Even if it doesn't change the way things are it can help you let go of some sadness. Sounds like you have a good husband and good friends, and feeling loved and appreciated can go a long way toward feeling better, so remember that you have all these wonderful people and animals around you who adore you.
It takes time. You started treatment a year ago, but if it's something that's been going on for 14 years it's going to take longer than that to pull yourself out of it. And some days you might literally feel like you have to be pulled around just to get through the day. Some days are better than others. Some days are more hopeful than others. Just give yourself time, have patience and understanding for yourself. This wasn't something that was created in a flash, and it won't go away in a flash. But you are doing some healthy, positive things, and you've taken some big steps. To me it sounds like you have accomplished a lot in a year - be proud of that!