Non communicative boss in a new job

I am three months old in a new job in a local field office of an international organization. Though I received a week's induction, I am discovering new areas that may need guidance as I adjust to the new environment. I was however shocked during one of the directors welcome, ' i want this strategy for this project, and if you don' t deliver results, i will disengage you.' This statement derailed my confident in this job- i have the right expertise for the job, and i wondered why they would hire me if they weren't okay with my credentials? I am further shocked to have older employees in the organization give me call warnings about what to do/ not do, and what to say/ what not to say and how to and not to. I have also been warned of employees & managers who betray staff to management and position them for firing. This has happened twice. In addition, my new boss is non- communicative, ignoring my emails and not providing feedback and guidance and I don't know how to progress. My boss doesn't also respond to sms, WhatsApp or even answer calls. When my boss does respond, it is to rush me through a process that I have to fast track. Am working from home, and all these is truly frustrating and stressful. I am about to complete probation and am seriously considering leaving as this appears to be a very toxic work environment. Being new am afraid to talk to HR about my experience as we all know HR is a friend of top management in an organization. I feel lost, What do I do?