Should I just walk away

Hard to explain all of this on this one post. But I been at my job for 20+years. I'm burned out from it. I have asked for time off but been denied over and over again. But I know my boss is talking behind my back. And is being two-faced with me. She tells me one thing but then tells another worker something else. She has other people tell me things and then she acts like they shouldnt be doing that yet she is telling them too. I've caught on to it all. I can't trust anyone or any anyone says there I feel like I'm losing it. But when I asked for time off I'm being guilty tripped that they will lose everything. I don't know what to do at this point I've tried talking to them. But I'm stressing them out they told people.