Welcome to the boards. I truly hope you do not have MS, but if you do, welcome to the MS boards and family!!
I think I would definitely see a MS Neurologist. You have had many of the prerequisite tests done; therefore, your time to diagnosis should be pretty good (I HOPE!!!). Total fatigue and muscle weakness- I can empathize. This afternoon I was so tired I took a short nap and awoke 3 hours later!
It is difficult to fight the fatigue. I can also empathize with your irritability and choice of words. When my brain is tired my speech, cognition, etc. are clearly "broken". Rest is my only cure.
Work and kids can stress you too. You need to look for trigger patterns and adjust your life. A daily journal can help you and may help your doctor too. Track when your symptoms present and what you were doing previous to that (what did you eat, what was the temperature.....). You may be able to ascertain your triggers and this can bring some normalcy back to your life.