You should not have been denied health insurance. The Affordable Care Act requires that health insurers accepts all applicants regardless of prior medical history. People with preexisting conditions must also be accepted, and the coverage for preexisting conditions must begin with no waiting period.
Apply for coverage through your state health insurance exchange.
That is a great question! A better one is why were you denied? There are extremely few reasons why you could be legally denied, and I'd sure like to know what their reason was. If they said "pre-existing condition", you don't want to insure through them anyway, as they are breaking the law, and probably aren't very trustworthy in their other dealings either. Count them as doing you a favor, and reapply with a different company, preferably one under the www.heathcare.gov site, where you might even qualify for help paying for the policy you'll get. Good luck, and thanks for asking!
Apply for coverage through your state health insurance exchange.