“You seem forced” can be used to indicate what you’ve expressed
Your meaning may have been gotten better than you think. “You seem forced” employs a fairly common usage of “forced”, indicating strain even though there is not a physical force. Note that “you look forced” in your question’s title is a little different, having to do with the way that “seem” refers more comprehensively to apparent behavior and “look” refers more to physical appearance.
Another way to say this that would be specific to tone of voice, diction, etc. would be “you sound forced” which could be hedged a little as “you sound a bit forced” and would be helpfully followed by a bit of explanation or a question, such as “is everything OK?”¹ or “do you feel you have to talk to me?”
Expanding on the “look”/“seem” difference in “you don’t look yourself”
With “you don’t look yourself”, it seems like you are saying that something about the other person’s physical appearance is unusual compared with historical data or some assumed expectation (e.g. someone’s face is green or streaked with tears and you assume they are not always that way, even if you don’t know them).
If you were to say “you don’t seem yourself”, your comments would be understood to refer to someone’s overall presentation. This could certainly include physical appearance, but is more often used to refer to someone’s speech, body language, and other aspects of behavior. I believe this phrase would fit the situation you described.
Note for “you don’t seem yourself”: Similar to “you don’t look yourself”, you would be understood to either be making a comparison to ways you’ve seen this person act before or ways you assume they normally act. For example, you think that the person doesn’t normally put so much emphasis on their words or deliver them in a staccato rhythm.
The note from the end of §1 of this answer applies here as well. Since you’re guessing at something about another person, it probably wouldn’t be a bad idea to describe a little more what you mean by what you’re saying. I personally think it would be appropriate to ask a question aimed at learning more about how this person is feeling and/or what they think about the situation.
As far as I know, that would be called takeout (sometimes referred to as takeout food). At least, that's what I've most commonly heard my American and Canadian friends say when talking about a prepared meal that you take home with you or someplace else instead of eating it where you bought it. I guess the reason it's called takeout is because you literally take it out of the building.
Examples:
I would like a medium French fries, a bottle of coke and a hamburger. Make it takeout, please.
Although that would probably work, a more common way to say it would be make it to-go:
I would like a medium French fries, a bottle of coke and a hamburger. Make it to-go, please.
I think you use takeout more in other contexts like I got takeout for dinner last night. Not when ordering.
It depends on the type of restaurant too. For example, if you go to a fast-food restaurant, you would ask for to-go. If you go to a casual dining restaurant, you might ask for takeout. At a very fancy restaurant, you only eat there and taking it home isn't an option. Pizza is a special case though. If you go to a pizza place, you order carry-out.
Best Answer
The most "American" version I can think of is to do someone wrong. You would normally phrase it as he did her wrong although in informal, idiomatic speech you sometimes see it as "done someone wrong".