Completely normal!
In fact by the end of maternity leave (sadly I only got five months) I had just chilled out and tried to embrace it.
In the mornings I’d get up and go for a walk, maybe throw something in the slow cooker for tea, but that was it. I considered that a pretty full day! If you’re rural and have a dog you must get to go on lots of nice walks - I live in a hot country so I couldn’t walk anywhere with the baby apart from across the road to Starbucks! But I made that my daily ritual and looked forward to it.
We were lucky and had a cleaner once a week so I didn’t have to do all the dirty jobs, but my biggest household management tip is this: set a timer on your phone for twenty minutes when the baby’s settled, and tidy as much as you can in that time! If it doesn’t get done in those twenty minutes, it doesn’t get done.
I did the same for food prep - ten minutes to chop all my veg and meat and chuck it in the slow cooker with some stock. It worked really well and made me feel productive and efficient 
I didn’t go to any baby classes. They’re not really for the baby, they’re for the mums, so if it’s just causing you stress and hassle then it’s not fulfilling its function. Maybe try to go once a week, since you enjoyed it?
But yes, it’s completely normal to feel like you do. I think we all picture maternity leave very differently to the actual reality. But I wish I had had longer, so do try to enjoy it as much as you can (not always easy, I know) and remember that looking after a baby is enough work without trying to do loads of other stuff as well.