First, and most importantly, please remove all personal information from this post and remove your confirmation number. Second, this is a customer to customer forum so we can only provide advice, you'll need to call Southwest to get any actual action completed.
Standard process when you cancel a flight is to receive travel funds which can be used by the same passenger as the original purchase and must be used for travel completed within one year of the original purchase date. Exceptione to this are very rare, almost unheard of. After the one year you can usually call within 6 months of the travel funds becoming expired and request the expired funds be converted to a travel voucher. This typically reduces the value of the funds by $100 and gives you another 6 months to use the credit. Given you have a medical reason and unknown date of future travel Southwest may choose to make exceptions to policies, or they may not. You'll need to call Southwest Customer Relations at 1-855-234-4654 to get an answer. This is also an example where travel insurance would help provide refunds when airline policies don't.
--TheMiddleSeat
