Did your position require that you sign a payback agreement? If so, have you read Section 11.4 on Payback on
this page? You do not appear to meet the waiver criteria found in Section 11.4.3.4.2. Since you say you have received eight months of support, I would guess that you will owe some service, to begin within two years of your departure, or that you'll have to pay back your stipend for those eight months (stipend only--plus interest-- if you're at an educational institution--other costs as well at other types of recipients).
I am not in your field, but I am fairly experienced in grantwriting and grants administration. I found this by looking up T32 grants and following the chain of links for requirements for trainees. The page at the federal website indicates these are 2010/11 guidelines, but since your grant would have been initiated during that year I suspect this is the correct set of regulations for you.