I came to US on H1-B visa from August 20, 2010 to April 30, 2011.

But due to misguidance I have filed 1040 for both 2010 and 2011.

But I feel that I didn't pass the substantial presence test for a resident alien now. I am not sure till. Please correct me if I am wrong.

Now am little scared, if in future the above thing will cause a problem to me.

What to do now. Do I need to file anything different for these two years. If so what forms and how long it take to get corrected.

This is a common error.

You can fix it by amending the returns with Form 1040X and attaching Form 1040NR.