Toxicity at it's peak

Hi All, Need your suggestion on the following scenario of toxicity. Currently working as a scrum master for Salesforce support project where except me other leads and managers are in the project since 7 years, I joined 2 years back. Ever since I joined post ML I have never felt included it's always like I'm left out, targeted bullied and mistreated yet I kept working with a hope they will understand my worth after a while. But things turned out to be opposite. Now I am completely ignored, none of the concerns are heard or addressed and overloaded and I'm being tagged a negative person when I am raising concern in the utmost polite way. Consider the current situation fearing to ask for release and at the same time feeling so frustrated and stressed that I can't sleep at night thinking of how bad I'm being treated and I can't do anything. This is a small Branch and not having ample of project scope. Please suggest how to tackle or advise what I do?