Most troubling are the words 'drug contacts' with the key word being 'drug'. Set aside everything else if he's hanging around with the same crowd/culture that got him into trouble that's a relationship deal killer alone, especially after years of issues. Throw in the deception and sneaking around that's it.
Afraid you are seeing part of his true character, that's not the drugs he was already ethically challenged so to speak. I'd say the drugs just allow him to act on urges & thoughts that run thru his mind sober or not.