About This Mac > Storage is fiction. Do not use it because the information is not reliable. The "Other" category is just that. A made up category that does not really exist on your computer. See What is 'Other' and 'Purgeable' in About This Mac? If you have only 351MBs of free space on your SSD, then remove as many files as you can to an external drive. You do not have enough space on such a small SSD to store anything more than what is essential. The rest of your data should be kept on external devices. A startup drive should maintain a minimum of 20GBs as free space. OS X will take up as much as 50GBs which leaves about 50GBs or so for your data storage needs.
Given the info you just provided, I would predict that continued usage of the drive, without shedding a lot of your data, will eventually corrupt the drive's directory and boot block. This will render the drive unusable. You would be forced to erase the drive and lose all your files. The following can help you avoid such a disaster.
Get Correct Storage Information
Do not use the information from the Storage section of the About This Mac dialog. Ignore the Storage information as it is typically wrong. To find out the correct information for any disk: Select a Desktop disk icon. Press Command-I to open the Get Info window and look at the topmost panel displayed. You will find the disk information displayed for Capacity, Available, and Used. If you have more than one disk/partition then repeat for each one on your Desktop.
The categories found in the Storage section of About This Mac is simply an arbitrary way of displaying files on your drive. There are no such categories actually on the drive.
How to Free Up Space on The Hard Drive
- You can remove data from your Home folder except for the /Home/Library/ folder.
- Visit The XLab FAQs and read the FAQ on freeing up space on your hard drive.
- Also, see Freeing space on your Mac OS X startup disk.
- What is 'Other' and 'Purgeable' in About This Mac?
- Files That Make Up the 'Other' Storage Category, and How to Remove Them
- Free up storage space on your Mac.
- See Where did my Disk Space go?.
- Be sure to Empty the Trash to recover the space.
- Replace the drive with a larger one. Check out OWC for drives, tutorials, and toolkits.
- Use OmniDiskSweeper or GrandPerspective to search your drive for large files and where they are located.