If you are in UK try Barclays Bank Travel Insurance. (May need to open current account with £20 to qualify) Then £18.50 per month. Cover for diabetes for small extra fee and extend cover past 31 days. It is multi trip cover but you can get out after 6 months.
Get access to airport lounges and if a car owner rac cover all inclusive.
Ask your Dr for three months worth as I did. Buy a cool insulin travel bag on Amazon for £12-20. Have copy of your prescription with you to show at Thai airport (if asked). No issues no problem.