I get asked this a lot !

I don't use cannabis but I use a legal derivative called CBD - it's good as a painkiller and it really dampens down my PTSD anxiety without any intoxicating effects (minor a nice relaxed sleepy feeling)

However, like you mentioned, it helps to alleviate the symptoms temporarily, but I'm more concerned about the internal effects the disease has and it's course on my life and future - cannabis unfortunately doesn't help wit that.