Constantly feel incompetent despite trying to 'challenge' myself

I feel so useless, I want to say things and do things to help others but it all seems stuck in my head and I can't get it out.

I found some volunteering over the holidays (I'm a college student btw), I've actually volunteered before at a lot of places, homeless shelter, charity shop, ambulance service, tutor, library, so many but I end up being useless and barely opening up and then stopping. People say social anxiety will go down as you go out more but I feel as incompetent as before, I can talk sometimes but overall I'm frozen.

The volunteering is at a summer camp and I supervise kids and we can also run our own activities with them not that I've done that, this has solidified out of everything I definitely won't work with kids or teenagers as a teacher because I don't particularly feel like I could do this for more than a few weeks at a time.

But anyway, we were walking the children back somewhere which involved crossing the road and one child is especially overactive and he's a young boy (around 5) so I follow and watch closely rather than going up to the kid because I could just stop him at the lights. Some of the older kids started shouting and one of them called me deaf and wanting to kill the kid just because I didn't hold the kid's hand and just walked with them and then I burst out crying. I'm also on my period maybe that also made me cry faster, I don't usually cry that fast. It was a little embarassing, maybe I should've taken the child's hand from the start because they're young but I thought just keeping watch was fine because the kid stopped at the crossing anyway but it was one of those kids who are very unpredictable.

Idk, you know when it feels like your anxiety makes you feel less responsible than teenagers who are younger than you? I'm trying to also comfort myself by saying I am a student who's barely out of being a kid myself but I constantly feel incompetent in many situations when I'M supposed to be the adult.

I wonder if I'll ever manage a job or a life of my own at this point. Feel like letting go.