How To Reduce The Pain In The Leg Which Is Getting Worse?

I have had pain in my left leg for 1 month and seems to be getting worse. I t hurts when I ve been sitting down for a while then eases a bit when I walk. It does feel less painful when I take pain killers. I ve had sports therapy on my left hip and thigh (apparently I have tight muscles or does he want more money from therapy to ease themhltilawtonh?)which sometimes helps but sometimes doesn t. What can I do I am going to Japan on a touring holiday and will be doing a considerable amount of walking sightseeing. My GP has given me painkillers and I don t wan tan investigation as it will effect my travel insurance.