I sold insurance for 10 years and yes, it's common to deny anyone that has a serious health problem for individual coverage. Groups will cover you, but only for small amounts usually. There are some companies that will cover you after 5 years for limited amounts, or after 10 years for more.
The policies that are advertised on TV will only be for maybe 10,000 or less and they usually will not cover you for the first year or two, then the benefits increase each year until you reach the full 10,000 (or however much the policy is).
You will just have to make several calls and ask if they have any policy that will cover someone in your condition.