Surprised it's not been said yet but there's a big difference in a colleague bringing you food to work and you turning up at their house after hours.
I've had plenty of women bring me food at work, some even had boyfriends and would say they are making extra to bring for me.
However turning up at my house is a different thing altogether.
Her boyfriend thinks it's inappropriate because it is. It's not your fault, no way you could have known she'd say no, but don't take it too personally.
Bear in mind your title says bringing you food "at work" and during this thread, you've latched on to other replies about her visiting your home and ran with it.
She brings food to the office, you said you want to bring her food at home, misread signals, she said no, you felt rejected and caught feelings.
Dust yourself off and don't let this phase you, also don't **** where you eat.