What you’re seeing is most likely normal, not damage from cleaning.

Two things are happening:

1. Shallow depth of field — At a long focal length and relatively close focus distance, foreground and background grass will blur strongly.
2. Chromatic aberration / bokeh quality — The purple/green fringing in out-of-focus areas is consistent with chromatic aberration, and that lens is known to show it more than higher-end lenses. The “weird” blur can also be described as less pleasing bokeh.

So the image does not suggest that you broke the lens. It’s more likely a combination of the shooting setup and the optical characteristics of the lens.

If you want to reduce it:

• avoid very high-contrast edges near the frame edges
• stop the lens down a bit if possible
• correct chromatic aberration in software such as Lightroom or similar RAW editors
• use a lens with better optical correction if this look bothers you often