Phone calls. Months can pass. Even if they're really important. Yeah, major anxiety.

Paperwork. Panic attacks even over the simplest of it.

Cooking. I used to really cook. All from scratch. Now it is just overwhelming.

Eye contact. I don't know if that counts as a task, but it is pretty much impossible.

Keep track. Pretty much of anything. Even it was JUST in my hand. In public I need to keep things ALWAYS in hand. If I set it down without retaining contact, chances of leaving it are ridiculously high. Not being able to keep track also applies to trying to compare, or looking at more than one thing at a time, especially if it involves numbers. (Was that number the amount of money? The number of hours? The date??!! What was the number again? Wait -- what am I trying to figure out??!) Keeping track of time, it probably goes without saying, is a lost cause.

There are many more, but those are the major ones that come to mind.