Lean Burn

[84NewYorker]

My 1984 New Yorker with the 2.6l has developed a lean burn issue out of seemingly nowhere, I've replaced all the vacuum lines, replaced the carb with a newer reman, but to no avail, I've attempted to get the O2 sensor out, but I just broke the connector and made zero headway even getting the damn sensor to budge, these kind of things aren't very well documented, at least not in the places that I'm looking. And I'm having an issue with the electrical system. When I turn the lights on my volts drop from 14V to 12V, once I add the use of my turn signals or wipers it drops to 8V momentarily, if I want to defog the windshield at all in the rain and turn on the heat, instant 8V and it stays there until it stalls or I turn off the heat.
any advice is appreciated.

[84NewYorker]

replaced the alternator and that fixed the voltage problem, Idle is still super garbage. haven't replaced the O2 sensor, but I unplugged the current one, and that made it more regular, it doesn't fluctuate anymore, but it still runs like hot garbage, doesn't choke out, just idles poorly.