I resemble this remark; could you elaborate on just who you feel can be helpful to talk to?
I regularly check in with my manager about my performance and he's very forthcoming on it, yet I still don't believe I won't be found out and canned at any second and end up sick and homeless.
Ideally someone has already beaten you to the punch(Imposter Syndrome is literally item #1 when I take on engineers to mentor). Of my sample size of ~150 engineers across every level my success rate of having people say "Oh my god, I have that" is so far 100%.
More concretely though I would not look to anyone directly in your management chain for a variety of reasons. The best ways I've seen to address it is with a senior engineer or someone that you respect who's willing to take you on in a mentorship role. This should be something where you set aside time to talk through these types of issues(plus all the other wonderful inter-team stuff that comes up in development) over a 3-6mo period.
If you can't find that I will say this: I've found that it comes from a place of caring and giving a shit about wanting to carry your weight or be a part of something. I don't think it's possible to have a desire to improve yourself and not experience it on a regular basis.
The best way I've found to approach it is to recognize when it's happening, call it out directly and tell yourself that your brain is being an asshole in this specific instance. Something I've also seen work well for other people is to do a short list of the things that you work on each day. Review it at the end of the day and take an objective look at what you've accomplished, you'll often find that it's more than you 'felt' like you did.
Hope that gives you some direction. If you're finding you local resources lacking drop me a line at val at vvanders.com and see what I can do to help.
Talk with a therapist or even a life coach if you want to start there. That you notice these feelings and want to do something about them is a good thing. Talking with a professional is good because they can really narrow down what's happening and give you strategies and coping skills.
There are therapists who are well versed in imposter syndrome and help patients understand it and get better. There are also podcasts if you want to take a self help approach first. I mean it's free. I would look for licensed therapists who apply a CBT oriented approach.
For imposter syndrome you have to assess at the evidence you are not capable or otherwise a fraud. Is there anyone else at your work that you feel is an imposter? No probably not. Are you as capable as the average employee at your work? Yes! You have performance reviews as evidence that you are good! What would you advise a friend who came to you expressing that they felt the same way? Would you say they are most definitely an imposter? What is an imposter anyway? How would an imposter be hired in the first place? Recognize that these automatic thoughts are triggering your amygdala and activating the nervous systems fight or flight response.
Also, there's quotes from Richard Branson along the line that if you meet 70% of the job requirements you are qualified to take the job and you should just learn the rest of it on the job.
And remember that even in the worse case, if you are fired, fired! There are still companies and jobs/roles where you are or can be a superstar. You see this all the time in business.
A therapist. No joke. In my case it _seems to be_ a coping mechanism for anxiety. I'm so afraid that I force myself to be successful. It goes under the radar because it's seen as healthy to the outside world, but inside is turmoil.
It was put best to me: Don't tell the dog it's not a chicken, we need the eggs.
I regularly check in with my manager about my performance and he's very forthcoming on it, yet I still don't believe I won't be found out and canned at any second and end up sick and homeless.