Now without know what was in the baggie, we are in a bit of a difficult situation. This is because most items he would have eaten should have run their course or have come to a head in those first 24-48 hours after he ate it. To see such delayed signs and worsening now, just makes worried that Champ either had another baggie (and the contents have been releasing slowly over this period) or that we have more significant damage (ie kidney or liver damage) from what he initially ate. Therefore, this is unfortunately a real worry. Especially as his lack of stool despite eating raises concerns of a possible blockage as well.
In this case, I do appreciate funds are a concern. Still, this is a situation that one unfortunately can not address much at home. We need to keep him drinking +/- syringe fluids (he needs to be taking in at least ~2 liters per day based on his weight). If he is straining to pass stool, we can try adding fiber (ie a spoonful of canned pumpkin or all bran) +/- a GI lubricant (ie cat hair ball treatment, miralax, lactulose, etc) to his meals to try and help him pass what may be caught or any brewing constipation. Otherwise, we'd really want a local vet to have a feel of him to determine if there is a blockage +/- bloods to see if we have a toxicity/organ damage situation, and start symptomatic care to help address his weakness and help flush this out to stabilize him.
Now since you noted funds are a concern, I did want to leave you with some options that could help. If you have a VCA or Banfield veterinary hospital near you, then you might consider taking advantage of their free first consult offers. You can find vouchers for this via:
Banfield : (http://www.banfield.com/landing-pages/coupon).
Otherwise, you could consider checking out the Humane Society's database (http://www.humanesociety.org/animals/resources/tips/trouble_affording_pet.html) or ASPCA’s (https://www.aspca.org/about-us/faq/financial-help-my-vet-bills). Both have a lot of branches nationwide, along with ties to other assistance organizations, that can keep down costs and surely will be willing to help Champ through this serious situation.
Please take care,