I personally think that taking the probiotics despite the dextrose would be more of a benefit than detriment, but its hard to say how much dextrose it would contain. If they are a low count probiotic (like less than 15 billion), then it really isn’t doing much anyways…so you might consider waiting until July to get them. This is unfortunate.
I would consider calling some pharmacies and doctors in the area to see if they carry probiotics; there is medical grade probiotics in the market, and it might be easier to get them there than at a supermarket. You might just need to convince them that you have a yeast infection or had a history of taking antibiotics.
If you have access to (raw) milk, you could make your own homemade yogurt, water kefir, and regular kefir. If you drank a bunch of it, it likely would be as good as a weak low billion count probiotic.
Prebiotics is another option instead of probiotics. I mean, there is beneficial bacteria in your gut right now, right? Feed those guys and it might help in a minimal way.
Can you get items shipped to you? If you had a friend in a neighboring country (or uk) they could possibly ship you some probiotics.
A fecal transplant might also be something to consider…there is a very high success rate with these(90%) and it will introduce beneficial flora in the gut, flora that you once may have lost. Of course, consult a medical practitioner if you are interested.