Questioning my value in the team

I’m working in a small startup team and, unlike my colleagues, I’m being asked to step outside of my expertise and do things I’ve never done before.  I’m paid well for it, but I feel undeserving. A male colleague seems to find fault with me and my work in most meetings. He had a good go at me today in a group meeting. It got very tense. I turned my camera off because I was in tears. And thought: I shouldn’t have to put up with this. But also: he’s just pointing out my incompetence and perhaps I am incompetent. This is my great fear. I feel like walking. I don’t believe in myself and struggle with the constant second guessing from this guy. It’s not healthy. I don’t know what I should do.