Sounds like you are on a Non-OA visa if you got it at the Singapore Embassy so renew your insurance and do a border bounce just before your Non-OA expires (not your 12 month extry stamp) to get a new 12 month stamp when you re-enter (or a stamp up to the end of your insurance if less than 12 months).
Don't do it until your next extension is due or you will lose what's left on your retirement extension as the new 12 month extension based on marriage will kick in at the time of application