newlife,
well, your name says much! good for you.
you are doing what you need to. it takes time. we need to feel our grief, and then, one day, the sun begins to shine again. doing things like checking up on him, hoping he will change the way we want, keeps us stuck.
i too thought that perhaps my addict boyfriend might be with someone else, when he would dissapear for a day or two at a time, and be vague about his whereabouts. later i found that he was using - not pot but harder drugs. he, too, wasn't the kind that would step out on me. i know now it was always the drugs. when they take over, that's the only thing for them (although some do use other women i guess)
it helped me to know that the other love was drugs not another woman.
i have a hard time believing that only pot use would look like this. but, it doesn't matter. he is now out of your life, and you WILL get over this.
i'd also like to say that you did not waste 10 years. you had to stay in that relationship for those years to get where you are today, and to learn what you had to learn. sometimes it takes a very long time (to learn) and sometimes we go back to the same lesson with other people. i hope that doesn't happen for you.