I've heard the expression used "You present well". (It was by a social worker.) I think that it can be either helpful or harmful, depending on the situation. If you need help very badly, "presenting well" can keep you from getting it, because you don't look or sound or appear as though things are really very bad.

Overall, I think I'd choose to present well and just learn that I have to be assertive if I'm telling someone that I have a problem. I've found that good doctors often understand this, because they are usually "good presenters" themselves.

As far as trusting a diagnosis, an in-depth psychological assessment (I'm talking like 90 minutes-2 hours, not 2 days in-depth) asks lots of questions and asks them in different ways.

The conclusion is based both on how you answer those questions and the opinion of the interviewer. The interviewer will not just evaluate you on how you present, but on what you say.

Resources vary from state to state and county to county, but the state I live in (a red one) supports a few mental health agencies that accept patients that don't have health insurance.

You can call United Way at 211 and ask them if your county/city has anything like this or you can do an internet search for "psychiatric care for uninsured/no insurance for MY COUNTY, MY STATE" and you'll probably find some sources.

If you have health insurance but it has lousy mental health coverage, like I used to, it still doesn't hurt to check with the state-supported agencies. Sometimes they will still help you, or help you for a low co-pay.