Is this a meltdowm

I'm currently waiting for an assessment. I'm trying to keep a diary of my feelings, emotions and reactions to situations I find difficult or when people have to help me through situations. Today I was trying to read some instructions, this is a task I find highly stressful. I struggle to take in the information so when I've read a sentence and moved on I have forgotten what I read previously. I get more angry at myself, then I start fidgeting, pacing around then I start shouting and swearing at the instructions, I get more upset and start crying. Them I'm in such a state I don't know what to do I'm angry and crying. Eventually, when I can no longer cope, I call my mum who knows exactly what I need, after all she has had to do this most of my life. A calm voice, talking quietly, reassuring me it's not a big issue and then talks to me about how we can resolve the problem. Is this a meltdown?