I am not the parent that this child deserves.
Sometimes we just expect too much of our selves. We are all human. None of us is perfect. We all get exasperated and say things and do thing in the heat of the moment that we wish we could take back. Instead of trying to "fix it all", take a deep breath and try and pick one single thing to focus on and allow yourself the luxury of letting the other things slide. Maybe you can both agree to lower your voices when speaking to each other and when you find yourself losing it say "I can't have this conversation now, please give me 10 minutes and we will try to talk again." Then go somewhere quiet and pull yourself together. I know this is really hard to do with an aspie because trying to understand the reasoning of someone who is viewing the world from a completely different lens than you are is difficult. I think society breeds us to think that our children would be perfect if we were just "better parents". That is a load of poo. Your son sounds a lot like mine. I found the years from K - 3 to be the worst for us. Second grade was a nightmare. But as my ds started to mature, things did get better. Every grade since has been an improvement over the year before, in terms of his coping skills, his flexibility and his interaction with other people. There is light at the end of the tunnel even if it's hard to see right now.
Please don't be too hard on yourself!
You'll hear this alot, but try not to beat yourself up.