Hidden disability

I've started playing ultimate frisbee. We do this as a family.

I'm not as skilled as most people, I'm a little unfit at the moment and I have not quite got the hang of the rules and then there is my hidden disability. I don't go on about it. No one but my family know and they don't always remember. I'm partially sighted. And it's not a big deal the vast majority of the time. But it effects my ability to understand depth of field. And in the fast pace of ultimate frisbee I struggle.
And today it got to me. I usually laugh off not being very good but I felt got at. I didn't say anything but my lack of skill meant that some players wouldn't include me.
I don't even bother to try tennis or squash because I get frustrated by constantly picking up the ball. But in a team game I thought it would be different. My brain will learn a different way to 'see' if I'm given the chance. In roller derby this was true, I learnt to look at shadows or to turn my head just one way, or listen out for changes.
It's unlike me to give up and despite wanting to walk off the pitch I stayed until the end. But right now I don't want to go again. I feel excluded by some.