In a situation where one partner makes less money than the other, you would normally work out a 30-70 split or a 60-40 split, whatever works financially for you both. He makes enough to live there on his own, he should NOT expect you to pay 50/50. That's ridiculous and completely out of your means.

You SHOULD NOT split the cost of furniture, how will you evenly divide this up when you break up? It doesn't make any sense. You buy the pots and pans, he buys the kitchen table. When the relationship ends, you take what you paid for. This leaves nothing to disagree over.

And you really should never give someone else your debit card, or take their card. Don't share your pin, don't do anything like that. You're not married. It's just stupid.

Realistically, you cannot afford to be living on your own with the job you have. Your total bills in a month should not exceed one paycheck, otherwise you're going to be living paycheck to paycheck each month with no savings to fall back on. I'm sure you want your independence from your parents, but it's smarter to stay home where you can live for free, and get a good savings, pay off any school debts, etc. (if this is possible for you, I don't know your family situation). Short term pain for long term gain.

You two are young, and you're both figuring things out, but he should not expect you to have no money because he wants you to pay for half of the things he has purchased. Him holding your debit card is the craziest thing to me. It's not up to him how much you're allowed to have. You worked, you earned that money, and in my opinion, unless you will be keeping the furniture when you break up, you shouldn't be paying for it.