I'm doing kettlebell swings with 18kg and finding it quite tough, is it the same for everyone?

‌People with incredible strength might find it easy,
but I'm feeling quite a lot of load on my forearms and lower body.
I've been doing this for 3-4 months now and I definitely feel like I'm getting a good workout,
but if my form slips even slightly, I could hurt my back, so I really have to be careful...