Worst mom ever 😢😢

My toddler over heard my swearing. It's been a hard week. Now he absolutely won't stop saying 'fuck' and 'that's stupid' which I know isn't a swear but it's not nice. He's 18 months old. I feel horrible. I've tried ignoring it and saying 'oh, Truck? Is that what you meant?' but he's been doing it non stop for a week. HELP I feel like a horrible parent.