I think this is a pretty normal experience for a new dev. I had a similar thing happen to me after one of my first projects, a guy who I didn’t even realize was my technically my boss pulled into a meeting room and asked me why I took so long. It bummed me out a lot because I thought I had done a good job and in a reasonable time. I got over it though, and apparently they did too; I ended up working there for another 2.5 years before changing jobs because I wanted to move back to my home city.