Basically a way to check my views/upvotes during a certain time frame

It already exists, to tell you.

Where can I find it?

It exists in the side panel, however you need to be a Moderator of the stream you submitted your post in. But you can also view it before it is submitted.

I'm aware of that, I was hoping for something more in depth, like upvotes, and being able to select certain lengths of time.

If you suggest it and enough people agree, your wish may come true.

that only shows the views though

Thats how stats work on imgflip, it shows views over time.