Final Result

The country's top histopathologist has found nothing so I'm going to be offered treatment. Bit of a relief but also worrying that the consultant was refusing to give it to me previously when I just wanted it over with and now nothing's changed, it seems there's no other option. Looking up the effects of sodium stibogluconate:

Sodium stibogluconate is exceedingly phlebotoxic. Pancreatitis is a common problem. The drug can be given intramuscularly but is exceedingly painful when given by this route. It can also be given intralesionally when treating cutaneous leishmaniasis (i.e., injected directly into the area of infected skin) and again, this is exceedingly painful and does not give results superior to intravenous administration. Sodium stibogluconate can also cause a reduced appetite, metallic taste in mouth, nausea, vomiting, diarrhoea, headache, tiredness, joint pains, muscle aches, dizziness, and anaphylaxis. -- Wikipedia