" i do love him more then anything else in the world.. but if i stay how can i help him"
You can't, it is all up to him. Your children should be your priorty, you should love them more than anything else in the world. IMO, your priorties are off kilter, children deserve at least one responsible parent, an active user cannot be a good parent...period.
Addicts lie, that is what they do, then they lie somemore. He has a disease that has no cure, it is just a matter of whether he is clean/sober and working a strong recovery program or not, that is it.
Might be time to work on you, and redirect your thinking, focus on your children, not him and his addiction.
Take some time to read the stickeys at the top of this forum and cynical one's blogs, lots of helpful information at your fingertips.