Joining a support group, not sure what to expect

A contact of mine suggested me to join a support group to find people with similar difficulties and talk to them.

I found a group nearby, but I'm a bit reluctant to go. I can feel myself making up excuses as to why it would not be a good idea.

• I don't feel like it would be helpful.
• I will feel like they have even more severe issues than me and I can't relate.
• It's a group with 10 people, so I feel like it's a bit too much for me. I feel like I will just let everybody else talk and be silent like usual.
• I was a bit sick in the past weekend and I'm worried about making other people sick (even though it's kinda over)

Anybody already went to a support group before, what was your experience?