Learn English – What period does in the last 2 hours cover

"I am confused" means "I do not understand."

From The Free Dictionary:

confused [kənˈfjuːzd] adj

1. feeling or exhibiting an inability to understand; bewildered; perplexed

"I am getting confused" has basically the same meaning; the implication is that they are in the progress of becoming confused ("I'm beginning to not understand").

A more common phrasing this (in my experience) is:

I'm starting to get confused.

This is a polite way of saying you've strayed into an area that they don't understand, and would like you to explain it differently or perhaps slow down. This also carries the implication that their confusion began recently; for example if you've been discussing something for an hour it's safe to assume that they're not confused about everything you've said, but that something you've said recently has confused them.

To address the source of your misunderstanding:

You mentioned that your guess as to what "I am getting confused" meant was "somebody thinks I am somebody else." If you actually want to say "somebody thinks I am somebody else", you would say:

I am often confused with Michael Jordan.

The with is very important; when you are confused with someone else, that means that very often people think you are that person. If this is something that has happened only once, not as a recurring pattern, you could say:

She confused me with [x].

Or if the event is still occurring, you could say:

I am being confused with [x].

Though this is unlikely, because usually if someone mistakes you for someone else, you clear the matter up immediately (that is, you'd tell the person they're wrong and the confusion would end before you would turn to someone else and tell them what's happening).

The question needs context. You need to ask your friend for more clarification. Relative dates can be quite confusing. If your friend wanted to be more precise in his question, he could add "from today".

"Last two weeks from today" means the last 14 days. Whereas "The last two weeks" could have many meanings depending on context.

Consider this scenario. Today is Friday, February the 3rd. I ask my friend "What are you doing this Sunday?" which would imply the next Sunday on the calendar (Feb 5). Or I could ask "What are you doing next Sunday", which could imply next week (Feb 12). Even though I asked about "next Sunday" it's not actually the next Sunday.

If somebody asked you "Where did you work last year?" they likely wouldn't mean literally all of 2016 or even the previous 365 days. There would likely be more context to it. Consider this conversation.

Judy says

"Thanks for coming to visit me on my Birthday!", to which I reply

"My pleasure! It was easy for me to get here because my new office is just around the corner."

"Where did you work last year?"

"On the other side of town."

Judy isn't asking me what my job has been for the last 365 days, she's asking me where I worked on her birthday last year.

It is a confusing topic that native English speakers still get confused about.

In your specific scenario, it wouldn't be rude to ask him "Do you mean this week and last?" or "Do you meant the last 14 days?" or "Do you mean last week and the week before?". I personally have found it common to ask for clarification of dates in casual conversation. Legal documents and conversation where it really matters would likely have explicit dates.