iPhone storage filled by Other

I have an iPhone SE 16 GB. The storage is full. I delete apps and make more space, then the Other catagory gets bigger and the storage is full again. How can I stop Other from growing? How can I make Other smaller?

Please do not suggest I use iTunes. I cannot use iTunes since I have a Chromebook. I think the next phone I buy will not be an iPhone since I can't afford to buy a Mac just to maintain my phone...

Thanks!