When you say separated, do you mean legally? If so, your separation agreement controls. If not a legal separation there is no restriction on what the spouse does with regard to health insurance.
If you're in a divorce case there are restrictions - and how they would affect you is something you should discuss with a local divorce lawyer.
As always, do not construe posts as legal advice but as "attorney advertising" and you should always consult with a lawyer on any legal matter.
You have certain rights with respect to health insurance under the new law. You should consult with counsel.
In the meanwhile, check with DSS and other government agencies to see what health care is available to you at the moment.