Mate, this sounds eerily familiar. With the one difference that you're not yet as bad as I was when I decided to quit for the last time. Bear in mind, nobody but a doctor can give you medical advice- and if somebody does, listening to them is a bad idea.
That being said, a tolerance of 15 standard drinks (I assume you mean American measures- UK units are about half of that, I think) is not normal. A normal person would be out cold, and not in any shape to do anything but puke after something like that.
I got to a point, at the end of my last stretch, where that much was needed just to keep me from having withdrawals. No buzz, no feeling good, I needed a bottle of vodka just to feel "normal". Its been almost 9 days sober now, and I still feel the after-effects. The twitchiness, insomnia and anxiety mostly. Writing here helps.
Food for thought. You don't want this mate.
Can you drink just 2 beers and be normal the next day? I dunno. Can you? Have just 2 beers I mean? Or are you like me, and 2 beers turn into "meh, I can have two more, I'm no *****", turns into "**** it, I can be late to work tomorrow, three more", turns into "screw it, I'll buy a bottle of vodka and mix it with coke to keep my buzz going throughout the workday, nobody'll notice". Up to you to answer that question. All I can say is, at first my answer was "yes". It didn't keep.