health insurance for chronic disease

[14all]

Hi,
I am an expat here and about to switch to a local contract as my sending contract is expiring. Option is to localise (preferred) or go back home. I am under ongoing long term medical treatment (chronic disease with average costs around 1500-2000 SGD/month) which is still covered by my home-insurance. The employer offers only "standard" sick insurance which does not cover already existing diseases. How can I get an optimal health insurance coverage here?
Appreciate your advise and thanks in advance.

[You can try]

asking your existing employer, who is the existing health insurance provider. If it is an international insurance provider, the insurance policy may be portable. This mean that you can bring the policy with you, when you change job, by paying for it by yourself.

It has been done before.