Well its problematic in that it is impacting his behaviour and his marriage (ie making you unhappy/unhappier/more anxious). He is getting drunk (slurring) and it is above the recommendied maximum -guessing around 40-60 units? So it may not currently be affecting him physically, but if this continues it will increase the risk of physical health issues eg blood pressure, stroke etc, as well as increasing his risk of accidental injury.
But on top of that you say his drinking has increased, and and you are both unhappy. In that situation he might well go on increasing his intake, and he risks dependency even if he isn't dependent currently. And once he is dependent, that is a whole world of pain for both of you.
My advice is for you to address your own unhappiness as an individual, work out what you want and indeed, what you need, and act accordingly. I assume to stay in the marriage you need for you both to take active steps to sort out your unhappiness (individually, and any problems in your marriage), and for him to sort out his drinking. Otherwise the only way for you to improve things for yourself, will be to leave.
You cannot do anything about his drinking or his individual unhapiness. So if he won't, you may need to let him go.