Help! Solidarity needed

I am struggling with my 18 month old, all of a sudden since he turned 17 months he's been throwing tantrums, wanting to be held 24/7, refusing to eat most meals, does not listen he has been throwing his spoon on the floor as an indicator he's finished his meals for the past 2 months every meal without fail. He's also become a little aggressive slapping and hitting me. The childcare yesterday told me on pick up, we need to correct his behaviour because he's starting to hit kids. Idk if I'm not disciplining him correctly but I've been a good mum, take him to library sessions twice a week, make creative meals, read to him everyday, Create different meals he may like, I feel like I'm failing. Just need some advice does it get better? What can I do?