I just need some encouragement.

I'm a step mom. I need some encouragement that I'm doing a good job..
I raised these twin boys from the time they were 2 years old (they are now five). Their birth mom has been in and out of their lives for ever. Ever since I had them.. 
they are diagnosed with autism. And it's been very difficult at times raising them. 
Thayer mother is not the best.. she's angry, hardly calls, and  isn't in the boys lives. 
I guess what I'm asking for is just some encouragement. That I'm a good mother for these kids. That I'm doing a great job. 
Now I know none of you people know me. Just kind words are needed.