To my understanding it should be possible to "double spend" this transaction (back to your own wallet) with a sufficiently high fee so it gets confirmed.
I'm trying something similar with a stuck transaction of mine, the only problem seems to be it is still on the mempool.
Your's should be the ideal candidate to verify this approach.
Alternatively you can simply try to broadcast the transaction again. However if it has a low fee it is unlikely to be confirmed anytime soon at the current situation (200k+ unconfirmed TX in the mempool).
I would love to test out this double spend method, but I do not have sufficient bitcoins to resend this transaction.
It's a fairly high amount.
I am not home currently so I will get the TX to you later tonight