DO is used for emphasis. In speech, it is stressed (except in the uncontracted negative).
The 'emphatic present' is: I do like; I do not like (I don't like), do you like?
With auxiliary BE and HAVE, and the modals, the auxiliary/modal receives the stress in speech.
An alternative way of giving emphasis in your example would be: I really need to se a lawyer.
Student or Learner