I really have enjoyed reading these posts - now I know I am not alone!
Sounds like most of us are "normal". We get frustrated and we yell sometimes - we are human and we are moms! My husband is in Iraq and I find myself yelling at my twin 3 year olds more than when they were younger. Part of it has to do with their ages and part b/c my husband is gone and I have more stress. I am sure when he comes back I will still have the occasional melt downs with the kids. The important thing is balance and acceptance - yelling should not be a norm, but should not be seen as failing as a parent.
The Pediatric Care Center on Old Georgetown Road in Bethesda has been great for us. They will meet with you before making an appointment to see if they fit your needs. I love the docs and staff. Good Luck