What am I doing wrong?

I cook with this daily. After cooking, I dry it on the stove and then coat with a thin layer of veggie oil. I wash it gently with water and a chain mail scrubber. Every time I set it to dry on the stove, there are exposed rusty dry spots and uneven seasoning. The bottom of all my cast irons have this build up of cracked seasoning (?). I also oil the bottoms for fear of rust. I don’t cook meat or use animal based oils except for cooking fish in it once in a while. I do sometime make acidic things like tomato sauces in it. Please help! And please be nice! I have been working up the courage to post in this sub. And please don’t say “just cook with it”. I have been doing just that and clearly I’m doing something incorrectly.