how many glasses are in a 750 ml bottle of wine?!
There are about 5 "drinks" in one 750ml bottle of wine (a drink being the standard 5 oz of wine) so 15 in 3 days. The short answer is yes this will hurt you in the long term. And eating and drinking healthily during the week doesn't affect the damage the alcohol does in the slightest, that's not how the body works (not that eating and drinking healthy doesn't help in other ways). There's no way to "detox" from alcohol other than letting your liver do what it does best, process and filter toxins. Problem is it can't filter and process everything without taking damage to itself. The other problem is is that one of the compounds your liver processes ethanol into is acetyl-aldehyde, a toxin in its own right, and let's not forget the large amount of empty calories contained within alcohol. If you're a female it's especially bad because alcohol abuse significantly increases the risk of breast cancer.
To put it into perspective, the accepted healthy drinking amount is one drink per day. So you're drinking over 2 weeks worth in 3 days.
The psychological definition of alcohol abuse (no matter what your other diet is) is more than one drink (shot, glass of wine, etc.) in one hour. That sounds excessive, but more drink than that is considered by definition, abuse.
If you cannot count or estimate how many drinks you are having each weekend, then you have an alcohol problem.
Fish oil is good for your cholesterol. Keep taking it.