Trying to stand up

My son is finding anything he an to try and pull himself up into a standing position and he keeps falling and hitting head pretty loudly. He does this from sitting position too and it's freaking me out a lil. Ftm. How do you stop them when he does it super fast and constantly. I need help 🙁

I have been putting as many pillows down around too as I can but it seems to make it worse cuz it's more for him to play on