This had been eating at me for a while before I eventually got fired for essentially being burntout and unproductive. I thought I could persevere through it as

This had been eating at me for a while before I eventually got fired for essentially being burntout and unproductive. I thought I could persevere through it as the companies values changed to no longer match my own, but I couldn't. It's better to leave as long as that option is available to you.