Medical Cannabis for PPMS

Hello everyone, I have never used any form of ‘social media’ so please bear with me if I get things wrong on here. I am a 73 yr old guy with PPMS. My main issue (there are a few) is foot drop and loss of control in one leg. I am told there is absolutely no medication available to me as I have a ‘good’ leg and any intervention could compromise that. I read of man in Australia with PPMS who after taking cannabis was able to throw away his walking stick, reduced many of his MS symptoms, and felt alive again. He said he used a very large amount of cannabis, but gave no details. I have been using medical cannabis (50% THC, 50% CBD) by prescription for some months but have seen no improvement as yet. The neurologist has suggested that medical cannabis might not be for me. He seemed to have little experience of treating MS. My plea to the community is - does anyone have any experience of using cannabis to assist mobility, and if so, what dose/quantity of cannabis achieved that, and how long did it take to get positive results?