To me it looks like you still have room. I see a clear path to the workbench.
When I was growing up the 16 X 20 barn at my parents was just large enough to put enough stuff that we actually climbed up the outside walls were there was no tin to access the second story.
Dad cleaned it out when he retired 15 years ago and now it is worse than before. Might just see if I can get a pic over easter to make you feel better about how much room you actually have left.