Long load times of webpage assets

I have a website that runs just fine on my local server. It's quick, responsive, and overall runs great.

But when I put it on the server of my domain host, sometimes it takes excessively long to load assets. For example, one 1MB png file took 2.31 seconds to load:

Chrome's Network Developer Tool reveals to me the following:

So is this likely due to poor implementation of my code or is it possibly a crappy server? (The company is subscribing at the lowest tier possible to host their content) My internet connection is quick so I doubt it's that.