I've run into so many jacka&& people like this it's unbelieveable. The fact is: You did the right thing to call that little punk on what he said. You had every right to fire him right than and there for comments like that. It's obvious you have an employee problem there. Mixing business and pleasure doesn't mix. You are not there to be their 'buddy' and 'pal'. You are there to manage. You and the other managers shouldn't be mixing your personal life with the employee's. Especially when there are drugs involved. What happens when they begin dealing at work? Everyone will lose their jobs.
It's hard because you feel like the outsider, unliked, unpopular, etc. But remember this is not social hour. You are a manager. You must demand respect and respect the employee's. Why are all these employee's still having breaks at the same time? Maybe if you can rearrange schedules so that they cannot all have the same break time. Mix it up. That will help stop some of the gossiping going on during these breaks.
Check out job sites like Monster.com, Yahoo.job, etc for more info about managing in a difficult situations like this. There are some great books out there too.
Don't expect to be liked all the time. Be honest with the employee's. Don't allow them to walk all over you.
This should also be brought up with the other manager's or above the manager's to keep outside influences coming into the work place.
Stay positive! Don't let them get you down!

Best Wishes,

Ocean