Stop bothering the other customers. Don't approach people you don't know. You're not in high school anymore. Then that's okay. Hostile, cranky drunks who instigate fights and use foul language will always get cut off and thrown out of the bar.
Bartenders are also wary of anti-social loners who sulk and brood and keep to themselves too much.
They tend to drown in their gloom and get silently shit-faced without anyone noticing. Impulsively buying drinks for strangers and large groups is immediate cause for bartender suspicion. You would never be that generous if you were sober. And Mother Theresa you're not. Okay, Sleepy head.