The past few months have suffered from pain from buttock down left leg making very hard to walk for any length of time

There is not enough information to give you an idea of what may be happening to you. I am not a medical professional, but when I had pain going from the buttocks, hip and down my leg it turned out to be serious. Are you having issues with incontinence (bowel or bladder)? Are you having areas of numbness? Are you having pain while sitting in a chair but not when you sit on a toilet? Does the trouble walking involve your feet also? If so get to a Doctor or emergency room.

It sounds like some kind of nerve related problem like sciatica or spinal stenosis etc. Ask your dr. for an MRI. I am 41 years old and although I have had symptoms for over 15 years, I was only recently diagnosed with congenital Spinal Stenosis. Good luck!