What Causes Severe Itching All Over The Body With Itchy Bumps On Penis?

Age :- 32
Weight :- 86kg
Height :- 6ft
Allergies - Penicillin
Living in Thailand

I have had sever itching on most my body including chest, neck, back of neck, stomach, waist, inner thighs,penis and scotum, behind knees, calfs, hands and feet (hands and feet having what looks like sweat blisters for 2months now, and eventually started to get red very itchy lumps all over my penis and scotum. They itch so much that I make them bleed from time to time. I have consulted a doctor several times here in Thailand (I live and work on an island and very limited choices!), and all he said was that is was definately not an STD and that it was a heat alllergy. All 3 times I went to see him, he precscribed the same drugs over and over. They offered very limited relief but once the medicine was finished everything comes back in force (I would like to point out the itchy lumps on the penis and scotum have at no point ever cleared up, although the rest of the rash on other parts of my body did!). I can't afford to keep going to the same doctor for the same medicine over and over. Please help me.....