Maybe you just have the wrong job, or with the wrong company or people.
I enjoy my job, and it gives me no anxiety whatsoever to think about it in my time off or to discuss what I do with others. I even come here on Fluther and talk about construction and engineering from time to time.
At work there’s a certain amount of pressure to “produce” and “get it right” and “be accurate”, but it wouldn’t be a job without those features, would it? So I accept those requirements as part of the job. But I don’t overly stress about them, either. If I can’t get something done “in time” despite my best efforts, then that’s the way it is. It’s up to me to see that happening in advance, though, and let my boss know so that he can either shift some of my other work load or assign someone else to assist – and that’s how work gets done on time, or schedules and priorities shifted so that “the most important work gets done on time” at least.
If you’re afraid of making mistakes or afraid of asking “stupid question”, then those are two sides of the same coin: not asking elementary questions is going to leave you wide open to making mistakes that would be considered “stupid” (if you hadn’t asked the question or clarified what you were uncertain about). As far as “getting into trouble”, if you’re doing the job and not goofing off, ignoring work, mis-prioritizing work or not clarifying instructions, then “getting into trouble” is in your own head. I don’t think I’ve ever worked for an employer who would get me “in trouble” for doing my job, even if I wasn’t doing it up to their standards.
As a new employee one of your primary functions, in fact, is “to learn”. Ask all the elementary questions you need to! If your boss or co-workers think that you’re “stupid” (or present that impression) for asking, then you’re definitely in the wrong place – and they’re the wrong people to be working with.
When I get overwhelmed with demands on my time, then I start to make lists (no, not “who should I kill first”!) of all of the various tasks and demands that are in front of me, and then I order the list: what’s most important (or closest to deadline), and so on. There are all kinds of ways to organize work; I’m not going to address them all here. But you need to find a way to “organize your work” and live within that – and within your abilities.
I would certainly not be looking at pharmacological solutions to your problems at this point. Absolutely not.
Learn how to work, first, and learn your particular job and how to prioritize and manage the processes. You should love or enjoy (or at least “not loathe and fear”) your work.