A credit card or debit card statement will just show where someone has used the card, not what they've purchased. If it was alcohol, then he could still put this on a card, and the statement would say 'Tesco £90'.
The fact he's withdrawing cash suggests it could be money he's using for a drug habit, likely cocaine or he could be using the cash to buy alcohol.
If you are out to work, and he works from home, then it would be easy enough to have a dealer come to the house (although you'd hope he'd have some sense not to allow this) or for him to collect it somewhere, during the day time. He's then spending his time in front of the TV, snorting drugs up his nose, once you're in bed.
Surely if he was coming to bed, even at 4 am, you'd smell the alcohol on him, if he was drinking?! If you haven't smelt alcohol on him, then I'd say it's drugs.
Your husband is an alcoholic, who is now likely using cocaine. Drug addicts lie and so do alcoholics. They become selfish individuals, who's only concern is their next fix or drink. Your husband has disengaged from family life, and is more than happy to leave being a responsible adult to you.
There may come a point when your husband is unable to function to do his job, and is sacked. You need to start looking at leaving, because your life will continue like this, until it's hit rock bottom. Your husband is dragging you and your children down with him. You need to get yourself out of the relationship, not just for your sake but your children's too.