How do I tell my husband?

Hi everyone.
I've been in a mono relationship for almost ten years, and married for half of those. Recently, I came to the conclusion that i have a strong connection to a friend who i have also known for a very long time. After some arguments and jealousy from my husband, I realized i didn't want to choose between one or the other, than I want and love them both in their own ways. I am terrified of telling my husband this because I think i will make him feel insecure, and Im not sure what is going to happen to our relationship if I tell him I also love someone else. So many things at stake. I don't know how to proceed. All I know is that I can't go back to a life of hiding and represing desires. But I also don't want to lose the two most important persons in my life.
Validate his emotions and talk about polyamory with him. Unfortunately, you might not be compatible with your husband. Initially, you agreed to have a monogamous relationship. You're going to have to accept he has a right to leave. You can try to convince him to change from monogamy to polyamory, but it's going to take a ton of work.