thank you so much

a few months ago I realized that i use "thank you so much" so much that i am not sure if I sound sincere and that i need to stop using it and start saying something better. As you can guess (or not) i have not been able to stop. I have really been worried about this, but now that i am aware of it I have noticed that it is used by not only others i come into contact with but also on TV and such. So i dont have to worry about using it but then again i dont like to follow the pack so i am going to think of something better to say.