Make a weekly task list with estimated time spent on each task.

Show your boss how many hours you have to work a week on a regular basis. Ask him for advice on how to manage them. Can he prioritizes the tasks and remove some less important ones off your list? or move some tasks to someone else who has less workload? I would tell him I can't work like this for long term. If he can't do anything about it, look for a new job. It is not worth your health. It sounds like it is not just your position, it is the company environment. I doubt a new boss can do anything about it. I would look for a new job ASAP.  You don't even need to mention this 2 months in your resume. While looking for a new job, prioritize your tasks and manage your boss' expectation. If other employees don't show to work, don't offer to do thier jobs. You have plenty to do yourself.