[davemp]

Just adding on to this great comment:

It can be hard to get over the anxiety to actually go out and participate in a club/sport. This feeling is pretty common for even people with good social lives. A trick I've found is just to evaluate your excuses. Usually you'll find that the reasons to skip going out are pretty weak and the potential upside to going is huge. Another one is to think about minimizing regrets. There's a comparatively low chance to regret going out over doing a solo activity.