Yeah, I can easily see how this is a nightmare for you.
I don't think you'd have any luck with flybe, as those planes to the Islands are so tiny and they'd probably refuse it.
Hebridean Removals offers a Man with a Van service -they do moving to and off the island,so perhaps they may be able
to meet you at Glasgow airport and then the ferry,etc?
Or you could try
D.R.Macleod as they also do removals and storage - I see their trucks going back and forth between Inverness and Stornoway all the time.
Can't imagine it would be cheap, but always worth a shot!
Good luck!!!!