The police and prosecutors absolutely will use what you said against you unless and until your attorney convinces the court that your rights were violated. Beyond that, it is impossible to answer your question without having access to the entire police reports and the ability to interview and cross-examine the police.
Yes. But when you ask for an attorney, it stops them from being able to ask you questions. Make sure you ask for an attorney as soon as possible, so that they stop asking questions, and you don't say anything that could be construed as incriminating.
This advice, despite its helpful nature, should prompt you to contact an attorney to confirm the propriety of any action taken that would affect your rights in a court of law.