IMO a line of credit should be set up as a CC tyoe account, that makes it easier since in effect that is what it is, borrow and pay back.
I assume the Opening balance equity entry is because the LOC has an opening balance
I would
1. delete the OBE entry from the register
2. delete or inactivate the bank account
3. create a credit card type account (no connection, do it from the chart of accounts)
4. make the following journal entry
debit OBE and credit the LOC account for that amount