I claim to have insomnia
Why would you lie about having insomnia?
It makes me feel important.
Claiming to have a medical condition you don't have will only lead to concern and confusion from others.
It's fine. I'm lying and I'll keep lying to cover up.
Continuing the lie will only make things worse, you need to be honest with people. If there were an accident and your friends told the doctors about a condition that didn't exist, it would lead to embarrassment and them not trusting you.