Just started therapy and driving myself nuts

I’ve had difficult thoughts my entire life on and off but I can never work out if I’m being dramatic or not. I’ve finally (now I’m in my 40s) started seeing a therapist because some work challenges have pushed me to a dark place. but I feel like a fake and like I’m acting when talking about my darkest thoughts. I genuinely believe I have no intention to kill myself but I have so many thoughts to do it but I just can’t work out if that means I’m being dramatic and fake and an attention seeker. To be fair, only my therapist knows about my thoughts but I feel stupid when I say what I’ve been researching and thinking but I know I’ll never do anything. What is going on? I even feel like a fake a fraud writing this - utterly riddled with self doubt