ElleDee this is a time for you to take care of YOU. Let him work out his own demons and let it be a blessing that you have some space to figure out YOUR NEW future without him adding his issues with that.

If you don't feel like you can tell him what you are doing because of past trials, (I am in the same boat) then don't tell him until you feel stong enough, and have some tools under you belt to cope when you do have the conversation. He may very well be a trigger for you? Have either of you been sober during your relationship? ( I have not been, my husband drinks but has no problem leaving a beer or stopping )

Either way, it may be the new sober you down the line helping/giving him the silent treatment/space if/when he works out his own issues with pot. Hugs!