I would recommend you look into finding some sort of case management service. You may be able to get some help here, but we are here because of cancer experiences, not because we have expertise or experience in labor laws, insurance, and other financial or legal matters. Check with his oncologist's office. They may be able to refer you to a support group that provides legal and financial advise. Additionally, many of those things vary greatly by jurisdiction, so what somebody from another state tells you may not necessarily apply in yours.
Cobra is a temporary continuation of health insurance at group rates. It has nothing to do with disability or life insurance. Generally, disability insurance pays a percentage of salary if the employee is not able to work due to a disability. So if your husband is still working, it is unlikely that disability benefits would be available. And if he is laid off, it is unlikely that the employer provided disability insurance would continue to cover him.