W.L.
I can't tell you where to find a support group but I can offer a bit of advice myself.
My husband and I have also have a 2 1/2 year old and have been trying to conceive our second child for about a year. I think I know why we have been having problems. My husband has just been very sick and was in the hospital for over a month. Probably the months leading up to his hospitalization his body was not working properly. I also am a little happy we did not conceive because if anything happened to that child my husband would have a lot of guilt.
I have been trying to keep a very zen attitude to our approach. I believe we are so lucky to have our healthy beautiful little girl when there are so many people who struggle to have one child. I think in time when it is right we will become pregnant again. In the meantime I am enjoying every moment of time with the child I have. I know once that second child comes around it will change our family forever and these precious moments I have with my child will change too.
Hope this Helps!