Playgroups and mothers' groups are like the first day of high school all over again. And don't worry, there are plenty of women out there who find they are just not their thing. I stopped going because I just found the whole thing stressful, and my son was just as happy at the park.

But, if you feel like you want it to work, here are some thoughts:
- read "how to win friends and influence people". An oldie but the wisdom is still valid today. One of the main points, which I find so true, is that if you want people to like you, ask them about their favourite topic - themselves!
- I mean this really kindly... Sometimes when we find ourselves in a difficult social situation it's easy to start on the whole "nobody likes me, think I'll eat worms" track. But often what we need to do is to toughen up and realise it's not about us. If I was at playground I would be seeking the company of the other mums, not the kids. They are probably trying to have a break - not avoid you. You can almost guarantee that the other mums there feel very similarly to you - they are tired, overwhelmed at times, lonely and seeking adult company.
- it sounds like you're unlikely to find your new best buddy there. So either walk away and do something else more fun at that time, or go but tell yourself it's for your son, and you will put up with it for his benefit, but don't have high expectations.
- he will get plenty of socialising when he starts pre-school etc. So if it really upsets you, let it go. Your needs are just as valid as your son's.

Hope that helps!