I'm sorry, but a vet is your only option here. First of all, it's virtually impossible to diagnose a beardie through a forum on the internet. Second, if we could diagnose the problem more or less accurately, it would probably need the attention of a vet anyway, unless you're able to take blood samples, examine fecal samples, administer injections, prescribe medicine...
Are you absolutely sure there are no vets specialised in reptiles in your country? Do you have a zoo where you live? If so, they either have a vet or they will know of a vet. I'm having problems believing that there are no herp vets in your country. Even in my native country, Norway, where reptiles are illegal, they have vets who take them.
Please, try to find a vet with a least some knowledge about reptiles. And I really hope you've separated them by now, by the way.