As much as I hate to ask what is a CBO?
As for the rest of your post the first solution that comes to mind of course is getting more funding. Personally I would analyze the funding that you did get in the past just to be able to see what programs are similar to it. In 12 years your non-profit organization received only 1 source of funding? Actually since a lot of the funding programs are on a yearly basis that is good that you were able to receive funding from that source for 12 years.
If it is any consolation just as grant programs are discontinued, new ones are being started.
I'm sorry to hear that your organization is closing and it might be a delicate subject matter as to why they would close after one funding source dried up.
You could see this as an opportunity to start your own non-profit organization - especially if you feel that strongly about what the organization was trying to do.
There is less of a stigma attached to non-profit grant funding because there is more of it available - especially from the government who awards the most in grant monies. Any grantwriter here will tell you that there is more than one available grant resource for a non-profit organization and again I am surprised that there was only one grant program in place for your organization