I forgot to deliver tutorials I feel like I have made a massive mistake of my career. I do tutorials for three subjects and although we are almost end of the first trimester but one of the module just started last week and I supposed to do the second week's tutorial today for that module. 

This morning I felt sick and i had constant headache. Even though I went in University and I did one of my other tutorials but I completely forgot to deliver tutorials for the module which started last week. I realised that I missed them after two hours. I never felt that much disappointed in my entire life. 

I have Phd submission soon and the fact I was not feeling well today seems to be the major cause and I also completely forgot to organise my calendar for this week.

Well it has happened now and I have informed the course coordinator. I didn't hear back from her yet. 

But my question is how today's mistake can affect my job? What likely consequences I will face? How should I handle this mistake? And finally, will they judge my previous performance based on this mistake? 

Cheers
I would say that you started rectifying the mistake by informing the coordinator. I would apologize sincerely and offer to to deliver the tutorial at another time. Mistakes happen and you are only a human and you were sick and that is understandable. Also, make sure not to miss any other tutorials in the future.