Well, you're worrying about it, so I'd say you know that there's a problem, maybe?
Medically, it's not healthy to drink that much, and it's not healthy to self-medicate with alcohol (I do both). But I (and most of us here, though not all), found it hard to stop when we tried. That said, I think there are people who can stop for a couple of weeks easily.
If you are worried, I'd say how about trying not to drink for longer than a couple of weeks?
I do think it cannot be the best thing to use for panic attacks - have you been on medication for them at all? It sounds tough.
Personally (if this helps, dunno), I get bouts of depression and self-medicate, and I'm pretty sure it makes it worse in the long term.
Hope you are ok - you sound pretty down, if I've not said the right thing I'm sure someone else will be along soon! 