i am constantly postponing rumination and it feels like the thoughts are "problems" stuck in the back of my head that i keep running away from, which makes it feel more like denial

My advice is to reframe the way you're thinking about it. Instead of it being a postponement, think of it as successfully not ruminating, which for people with OCD like us is a big part of the problem; so, good job! Also, you're not running away, you're simply not paying attention to something that doesn't deserve your time. Again, good job! You're heading in the right direction, so keep going with it.

can ocd be mild? like during school time it was way worse, way more rumination and thoughts and anxiety. now it's barely affecting me, do you think it's because i am not stressing much over school anymore? because i feel like at this point i don't have ocd

Yes, OCD can be mild and stressors do have a way of wratcheting up the anxiety and ruminations. The important thing is to learn how to manage the ruminations and anxiety so when you are in a stressful situation and the OCD starts talking, you'll be ready.

Very common for OCD, same happens to me.