it can be discouraging to be dropped like that and psychology does have an impact on how you ride. I would suggest that you give it few more times.

Being light does help to a point; but, like sunshine says, you need weight for strength. And its the balance between the two to be a good climber.

And being light, you are definitely disadvantaged on downhill where the heavy person is able to carry the speed.

Once you get dropped because of traffic light, it can be almost impossible to catch up. They are in a group drafting each other and you are not.

Overall, I think you did pretty well. So give it a few more times.

so don't beat yourself too much,
Smilingcat