Stope Payment on check

I recently had some work done on my car which is a 2003 jeep liberty. it came back that it had to have a new motor put in it.
It cost me 2600 to have this done. The place i had it done was a business that my sisters boyfriends brother owned. I have known him for over 14 years.
We had agreed to write 4 different check to pay for the work. the checks were post dated in the amount of a little over 600 each.
he was not supposed to deposit the checks until the dates on them.
the 1st 2 checks he deposited a couple of days before the date on the checks which in turn made my account go negative. so in turn i wrote him a letter stating that i was putting a stop payment on the last 2 check because he had broke our agreement to deposit the checks on the date that was on the checks. i sent him this letter certified and with a copy of the stop payment order and told him i would pay him the rest of the 1200 in cash.
well since then a lot of things had went wrong, my husband lost his job, i lost my job cause i went on maternity leave and of course i had a baby and with 3 kids now we got really behind.
i tried to call him numerous times and he would not return my calls, he called my husband and screamed at him and told him that we almost made him lose everything cause of the stop payment and my husband told him what happened and yet he just bought a new 500k tow truck to haul semi trucks but yet we almost made him lose everything.
i received a letter from the states attorney because he told them that i wrote them bad checks. i did not write them bad check i put a stop payment on them and i informed them of the stop payment.
i talked to the states attorney and she said that it was going to be taken to the grand jury on april 4, 2008 and if i did not have it all paid to him by then there was a chance that i would be indicted because of it.
i guess my question is what is going to happen with this. I am going to try my darndest to have this 1200 paid by then but what if i dont. I do not want to go to jail for him saying i wrote bad checks. he did not tell them about the two checks i wrote previous that he broke our agreement with nor did he tell them about the letter and when i told the states attorney about it she said that if it went to the grand jury all she was going to do was tell them ok this person wrote these checks to this person and they didnt clear the bank.
please help me what can i do.