I need to fill out the form I 601 and i asked an attorney and they said that we need a check up from psychiatrist

An I-601 is a hardship petition. If your immigration attorney feels that you need a psychiatric evaluation in order to submit the I-601, then you should listen to your attorney and obtain the evaluation.

I agree with my colleagues. You need to prove that your husband's removal from the USA or inability to join you will result in an extreme hardship to you and your children. Psychiatric evaluations are often included with these filings. Each case is different, which is why you should follow the advise of your attorney. Good luck to you and your family.