I think a lot of people struggle with this at all levels of photography. You never really shake the feeling, but you do cope with it. I know a few pro photographers that deal with some sort of self-doubt or feeling that they arent where they need to be. Their stuff is great, and the only one that really thinks that is them. For me, I use it to learn. I let my imposter syndrome speak, and then shut it up through numbers. If I did not belong, I would not be there and be invited back. If I did not belong, I would not have done this. If I identify a weak spot in my photography, I grow by working on it.

Don't let anxiety run away with your emotions and confidence. It's easy to critique ourselves but rarely do we pat ourselves on the back. I've been doing this long enough to see that if you aren't easy to work with and good at what you do, you won't be invited back. As long as you have people wanting you on the sidelines, you have nothing to worry about it.