This is weird, my therapist has just brought this up therapy.
I was a heavy skunk smoker throughout the end of my truama year, and then fruther into PTSD. I stopped for a while and recently became a heavy smoker again. I've now given up, though if I had a choice (i've lost my dealer) I would still have some handy so I could go back to using it as relief of anxiety on bad days.
My therapist has been researching the use of pot/skunk, and today told me that from what he has read, there is a problem when people use it to cope on a daily basis. pot or skunk alters your mind, and for me, it is used to 'blank off' my mind and my PTSD. The trouble is, he says... it isn't allowing me to process if I am using it to block. To overcome PTSD, processing is ultimately important.
So perhaps looking at the reasons you are using pot could help you to find your answer? Is it helping you to deal with things, or helping you to keep things under a blanket?