Was your camellia grown from seed? Camellia seedlings can be a challenge to gardeners as they take several years (6-8 years) to bloom.
What variety of camellia do you have? The variety you have may not be suited for your particular climate and thus will not open properly (or at all).
I would review the information in the following articles which discuss the reasons why camellia buds will not open. Hopefully one of the reasons will resonate with you and resolve your issue.
I would also review the article below, particularly the section “growing camellias” and make sure you are following all the plant requirements with regards to lighting, moisture and feeding.