Negativity is Contagious

Negativity is contagious and I am trying really hard not to catch it. However, I feel that at times there is a fine line between the normal need to vent and just having a negative attitude. For instance, I take Zoey to her speech group twice a week, and at first I was really happy to have other moms to talk to who were dealing with the same things I am. However, I find it hard to keep a balance between venting and maintaining a positive attitude. Is raising a child with Autism a walk in the park? No! But it's also not the end of the world, and it does no good to act like it is

So where does the line between venting and just having a negative attitude get drawn?

I can't change the fact that there are difficulties that we face on a daily basis. There are days were I just want to scream, and I find someone to vent to (so I understand that need). However, I'm trying to maintain a positive attitude and focus on the good things. I'm hoping that I can find a way to spread a more positive attitude to my follow moms without coming across as a know it all or judgmental (cuz there's a fine line there as well).