Boss threatening to fire me...constantly?

Okay so I've been at this warehouse for about a year now and the past 4-5 months my boss has been on my back every second of the day. No matter if I'm the only one working or I'm with a couple co-workers( all doing the same thing talking) and I'm the only one he says something too. he says smart remarks to me every chance he gets me alone and if there are other people around he will get someone else to relay his message( go do this or that). Now I've worked in other warehouses and this is by far the most out of control one I've worked in, for starters i was hired as a warehouse worker and he has me fixing forklifts, cars, and electrical things around the warehouse as well as my personal safety on half of the things I do on a daily basis. There are other people with seniority over me but he doesn't treat us all fairly. Last month i was waiting for an important phone call and i checked my phone and he walked out and told me if he ever see's my phone again he was going to run it over with a forklift. He is constantly coming up to me saying I'm either working too fast or not doing enough (which one is it). But most recently he has been saying "one of these times I'm going to tell you to go home and never come back". I'm at the point where i don't know what to do as I've applied for other jobs but the job market just isn't there, and he doesn't pay me enough to keep getting worked around like he owns me.